No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
LIBS analysis of crop plants
Abstract
A fast and cheap method for the analysis of macronutrients (K, P, Mg and Ca) in leaves of crop plants (wheat, poppy, barley and rape) using double pulse laser induced breakdownspectrometry (LIBS) is suggested. A commercially available LIBSspectrometer was calibrated with the aid of authentic plant samples previously analysed by AAS and ICP-OES after microwave digestion. The concentration ranges of K, P, Mg and Ca in the calibration standards were 30–66; 2.8–6.6; 1.0–5.6 and 6–24 g kg−1, respectively. Cryogenic grinding and powder pressing to pellets were used as sample preparation steps. Obtained LIBS/ICP-OES recovery values for authentic crop plant samples were 93–109% (K); 93–114% (P); 89–109% (Mg) and 94–110% (Ca). Six certified reference materials (CRMs) of plant tissues were used for the LIBS method validation. Recovery values of 96–101% were obtained for K and P, when the certified concentration of the element in the CRM was inside the concentration range of the used calibration standards. Substantial matrix differences of the CRMs and LIBS calibration standards seem to be a probable reason for the worse recovery results (58–99%) obtained for Mg and Ca.
... It is however still a challenging task to apply the quantitative analysis using LIBS, traditionally and commonly used for inorganic sample analysis (alloys, minerals…), to the analysis of vegetables or more generally foods. Several works have reported the use of LIBS for qualitative analysis of trace elements in plants [42,140,141], and in particular in leaves [142][143][144]. Quantitative measurements can be achieved with LIBS either with calibration curves, using reference samples, or by performing the CF-LIBS [58,121]. ...
... Very recently, LIBS technique was applied to milk powders for the determination of calcium concentration using the calibration curve method with a validation by ICP-AES [34]. Some recent works report the direct comparison between ICP-AES and LIBS for analysis of organic samples such as plant materials [141,144]. Comparing the analytical performances of these different techniques for the quantitative analysis of inorganic elements in milk powders is also the motivation of the present work. ...
This PhD work was devoted to the understanding of the laser-induced plasma on organic materials and theapplication of laser-induced breakdown spectroscopy (LIBS) to quantitative analysis of these materials. Itcontributes to deepen our knowledge on the physical mechanisms involved in laser-matter interaction, plasmageneration, evolution and expansion of the plasma into the ambient gas, with emphasis on plasmas induced onorganic targets. It also intends to improve the performance of LIBS for the analysis of organic materials. Thespecificity for organic targets fits the current focus of the international community working on LIBS, toimprove the control of the plasma induced on this kind of material which has a distinguished optical prosperitywith respect to that of metals, better known for laser ablation. It addresses also the growing need to apply theLIBS technique to organic materials for different applications in the environmental, food, or biomedicaldomains. The works in this thesis were therefore presented in this thesis document according to the followingorganization.After the General Introduction which introduces the scientific and technological contexts, Chapter Irecalls the basic theoretical elements necessary to understand the phenomenon of plasma generation by laserablation, and its evolution in the background gas. Ablation of organic material is emphasized. Procedures andtechniques of diagnostics of laser-induced plasma were then presented with a focus on the transient andinhomogeneous nature of the expanding plasma. Chapter II focuses on the generation and the evolution of theplasma induced on the skin of a potato, a typical sample of agricultural product. The characteristics of plasmainduced on a soft and wet organic target, such as a fresh potato, was something unknown when the thesis workstarted. These characteristics provide the necessary basis for the quantitative analysis of the trace andultra-trace metallic elements in these samples. Following this characterization, semi-quantitative analyticalresults were extracted from LIBS spectra corresponding to potato skin. Chapter III is presented in thecontinuity of Chapter II for the application of LIBS to the quantitative analysis of organic materials. Acomparative study on the analytical results with LIBS and ICP-AES for milk powders allows an assessment ofthe performances of quantitative analysis by LIBS for organic materials, and a validation of the CF-LIBSprocedure that we have developed. Different from Chapters II and III where attention was paid to trace metalelements, Chapter IV studies the behavior of the major elements that make up the matrix of organic material,which are 4 known organic elements: H, C, O, N. During the decomposition of organic material by laserablation, these elements can be found in the form of molecular fragments, or recombined into molecularspecies. We then study in this Chapter the evolution of these species as a function of the laser ablationparameters, the laser wavelength in particular. The thesis document ends with a general conclusion andoutlooks.
... In addition, many researchers employed LIBS technology to analyse to agricultural goods (Yao et al., 2013), plants (Kumar et al., 2014;Pouzar et al., 2009;Santos et al., 2012;Trevizan et al., 2009;Yao et al., 2010), wood (Uhl et al., 2001;Solo-Gabriele et al., 2004;Martin et al., 2005), food (Schroder et al., 2013), etc. and fruitful academic achievements are made. ...
Considering the diversity of soil contents, quality and usability, a systematic scientific study on the elemental and chemical composition (major and minor nutrients elements, trace elements, heavy metals, etc.) of soil is very important. Rapid and accurate detection and prevention of soil contamination (mainly in pollutants of heavy metals) is deemed to be a concerned and serious central issue in modern agriculture and agricultural sustainable development. In order to study the chemical composition of soil, laser induced breakdown spectroscopy (LIBS) has been applied recently. LIBS technology, a kind of atomic emission spectroscopy, is regarded as a future “Superstar” in the field of chemical analysis and green analytical techniques. In this work, the research achievements and trends of soil elements detection based on LIBS technology were reviewed. The structural composition and operating principle of LIBS system was briefly introduced. The paper offered a review of LIBS applications, including detection and analysis of major element, minor nutrient element and heavy metal element. Simultaneously, LIBS applications to analysis of the soil related materials, plants-related issues (nutrients, pesticide residues, and plants disease) were briefly summarized. The research tendency and developing prospects of LIBS in agriculture were presented at last.
... Although LIBS is still a new and little explored for measuring nutrients in plants, it has started gaining more attention over recent years (Van Maarschalkerweerd and Husted 2015). LIBS was successfully used to measure the concentration of Ca, Mg, P, K, Na, B, Fe, Cu, Mn, Zn and other elements in leaves of different plants such as sugarcane, soy, citrus, coffee, maize, wheat, barley, rape, poppy, eucalyptus, mango, bean, banana, lettuce, brachiaria, pearl millet, grape, rubber tree, tomato, cucurbit seeds and many others (Pouzar et al. 2009;Nunes et al. 2010;de Carvalho et al. 2015;Singh et al. 2017). LIBS was also used as a diagnostic tool to monitor the changes in the content of Ca, K, Na and Fe for rapid detection of drought stress in wheat and gardenia (Kunz et al. 2017) and to identify the nutritional changes provoked by bacterial disease in the citrus leaves and soybean (Ranulfi et al. 2017(Ranulfi et al. , 2018. ...
The ionome concept, which stands as the inorganic composition of an organism, was introduced 15 years ago. Since then, the ionomics approaches have identified several genes involved in key processes for regulating plants ionome, using different methods and experimental designs. Mutant collections and natural variation in the model plant species Arabidopsis thaliana have been central to the recent discoveries, which are now being the basis to move at a fast pace onto other models such as rice and non-model species, aided by easier, lower-cost of geno-mics. Ionomics and the study of the ionome also needs integrations of different fields in plant sciences such as plant physiology, genetics, nutrition and evolution, especially plant local adaptation, while relying on methods derived from chemistry to physics, and thus requiring interdisciplinary, versatile teams. Here we review the conceptualization of the ionome as an integrated way of viewing elemental accumulation, and provide examples that highlight the potential of these approaches to shed light onto how plants regulate the ionome. We also review the main methods used in multi-element quantification and visualization in plants. Finally, we indicate what are the likely next steps to move the ionomics field forward.
... Although LIBS is still a new and little explored for measuring nutrients in plants, it has started gaining more attention over recent years (Van Maarschalkerweerd and Husted 2015). LIBS was successfully used to measure the concentration of Ca, Mg, P, K, Na, B, Fe, Cu, Mn, Zn and other elements in leaves of different plants such as sugarcane, soy, citrus, coffee, maize, wheat, barley, rape, poppy, eucalyptus, mango, bean, banana, lettuce, brachiaria, pearl millet, grape, rubber tree, tomato, cucurbit seeds and many others (Pouzar et al. 2009;Nunes et al. 2010;de Carvalho et al. 2015;Singh et al. 2017). LIBS was also used as a diagnostic tool to monitor the changes in the content of Ca, K, Na and Fe for rapid detection of drought stress in wheat and gardenia (Kunz et al. 2017) and to identify the nutritional changes provoked by bacterial disease in the citrus leaves and soybean (Ranulfi et al. 2017(Ranulfi et al. , 2018. ...
The ionome concept, which stands as the inorganic composition of an organism, was introduced 15 years ago. Since then, the ionomics approaches have identified several genes involved in key processes for regulating plants ionome, using different methods and experimental designs. Mutant collections and natural variation in the model plant species Arabidopsis thaliana have been central to the recent discoveries, which are now being the basis to move at a fast pace onto other models such as rice and non-model species, aided by easier, lower-cost of genomics. Ionomics and the study of the ionome also needs integrations of different fields in plant sciences such as plant physiology, genetics, nutrition and evolution, especially plant local adaptation, while relying on methods derived from chemistry to physics, and thus requiring interdisciplinary, versatile teams. Here we review the conceptualization of the ionome as an integrated way of viewing elemental accumulation, and provide examples that highlight the potential of these approaches to shed light onto how plants regulate the ionome. We also review the main methods used in multi-element quantification and visualization in plants. Finally, we indicate what are the likely next steps to move the ionomics field forward.
... For quantitative detection, the height of some peaks is evaluated. Under laboratory conditions, LIBS was able to detect relevant elements like K, P, Mg and Ca in plants and soils (Pouzar et al., 2009). However, the sample has to be dried since water strongly affects quantification. ...
... Laser induced breakdown spectroscopy (LIBS) is used to assess elemental composition of a sample by analyzing optical spectra of a plasma, created by a high energy laser impulse. Under laboratory conditions, LIBS was used to detect relevant elements like K, P, Mg and Ca in plants and soils (Pouzar et al., 2009). However, the sample has to be dried since water strongly affects quantification. ...
... After cooling, the solution was diluted up to 50 mL, filtered and used for the minerals estimation. The mineral qualitative analysis was also performed using LIBS [54]. Briefly, Pulsed Q-switched Nd:YAG (Quantel Brilliant) was used for mineral analysis. ...
Recently, laser application in agriculture has gained much attention since plant characteristics were improved significantly in response of pre-sowing seed treatment. Pre-sowing laser seed treatment effects on germination, seedling growth and mineral profile were studied in Moringa olifera. M. olifera healthy seeds were exposed to 25, 50, 75 mJ low power continuous wave laser light and grown under greenhouse conditions. The seedling growth and biochemical attributes were evaluated from 10-day-old seedlings. The germination parameters (percentage, mean germination time), vigor index, seedling growth (root length, seedling length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight) were enhanced considerably. The laser energy levels used for seed irradiation showed variable effects on germination, seedling growth and mineral profile. The mineral contents were recorded to be higher in seedling raised from laser treated seeds, which were higher in roots versus shoots and leaves. The Effect of Laser treatment of seedling fat, nitrogen and protein content was insignificant and at higher energy level both nitrogen and protein contents decreased significantly versus control. Results revealed that M. olifera germination, seedling growth and mineral contents enhanced significant and optimum laser energy level has more acceleratory effect since at three laser energy levels the responses were significantly different. Overall the laser energy levels effect on germination and seedling growth was found in following order; 75 mJ > 50 mJ > 25 mJ, where as in case of fat, protein and nitrogen contents the trend was as; 25 mJ > 50 mJ and 75 mJ. However, this technique could possibly be used to improve the M. olifera germination, seedling growth, biochemical and minerals contents where germination is low due to unfavorable conditions.
... The mineral contents were estimated by LIBS technique. For this, dried plants were grinded and the mineral contents were estimated using laser induced breakdown spectroscopy technique (Pouzar et al., 2009). Pulsed Q-switched Nd:YAG (Quantel Brilliant) laser setup was used. ...
Effect of pre-sowing magnetic field (MF) treatments on germination, seedling growth and yield attributes in bitter gourd (Momordica charantia L.; cv Faisalabad Long) were investigated. Genetically uniform seeds were exposed to 25, 50, 75 mT generated by an electromagnet (rectified sinusoidal non-uniform) for 15, 30 and 45 min. The treated seeds were sown and grown under field conditions in experimental plots (2.4 m2) according to standard agricultural practices along with control. The germination, growth, yield parameters were measured by standard methods and for mineral contents, laser induce breakdown spectroscopy (LIBS) was used. The enhancements in germination, emergence index, mean germination time (MGT) and vigor index I and II were recorded up to 54.52%, 50.92%, 35.98%, 24.93% and 47.21%, respectively. The growth parameters i.e., growth rate (56.98%), leaf area (64.61%), root fresh weight (55.77%), root dry weight (76.16%), shoot dry weight (45.26%), shoot fresh weight (23.35%), shoot length (29.39%) and root length (17.78%) were also enhanced significantly in plants, raised from magnetically treated seeds. The chlorophyll contents (35.41%), fruit length (18.11%), fruit weight (14.93%) and yield (29.16%) and mineral contents were also recorded to be higher in MF treated plants group versus control. Results suggest that pre-sowing MF treatment has the potential to improve the bitter gourd productivity by enhancing germination, seedling growth, mineral contents and yield since this treatment is eco-friendly and also affordable.
... Colors of arrows refer to where the interactions have been described; see reference. From Baxter (2009). that focus exclusively on one or a selected few elements will, thus, be sensitive to alterations in the interactions. ...
Ideal fertilizer management to optimize plant productivity and quality is more relevant than ever, as global food demands increase along with the rapidly growing world population. At the same time, sub-optimal or excessive use of fertilizers leads to severe environmental damage in areas of intensive crop production. The approaches of soil and plant mineral analysis are briefly compared and discussed here, and the new techniques using fast spectroscopy that offer cheap, rapid, and easy-to-use analysis of plant nutritional status are reviewed. The majority of these methods use vibrational spectroscopy, such as visual-near infrared and to a lesser extent ultraviolet and mid-infrared spectroscopy. Advantages of and problems with application of these techniques are thoroughly discussed. Spectroscopic techniques considered having major potential for plant mineral analysis, such as chlorophyll a fluorescence, X-ray fluorescence, and laser-induced breakdown spectroscopy are also described.
... The practical quantitative aspects and relevant applications, as well as the diagnostic aspects of laser-induced plasmas have been discussed and summarized in detail [27,28]. With the development of laser and detection systems, LIBS has shown a remarkably wide applicability in many fields, including combustion [29][30][31][32][33], metallurgy [34][35][36], food [37,38], human health [39,40] and others [41][42][43][44][45]. The number of applications is still growing. ...
The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS) and laser breakdown time-of-flight mass spectrometry (LB-TOFMS). Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N2 were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application.
... This is especially true for vegetables that are in direct contact with pollutants present in the soil and in the air. Several works have used LIBS to analyze trace elements in plants (Sun et al. 1999;Assion et al. 2003;Trevizan et al. 2009), and in particular in leaves (Samek et al. 2006;Myriam et al. 2007;Miloslav et al. 2009). ...
Optical emission of laser-induced plasma on the surface of water extracted from fresh orange juices provides sensitive analysis of trace elements. This emergent technique promises applications with expected outcomes in food security or nutrition quality. Characterization of the plasma induced on such samples can represent a method to characterize the quality of soils where the oranges were planted. In this paper, we present the experimental setup and protocol that optimizes the plasma generation on liquid surfaces. We focus particularly on the detection of Ca, Mg, and Na. By way of stallion solutions (CaCl2, MgCl2 and NaCl), we try to determine the concentrations of these elements. We set as samples, oranges coming from Tunisia and Spain.
... The mineral contents were estimated by LIBS technique. For this, dried plants were grinded and the mineral contents were estimated using laser induced breakdown spectroscopy technique (Pouzar et al., 2009). Pulsed Q-switched Nd:YAG (Quantel Brilliant) laser setup was used. ...
... In general, the determination of nutrients in plant materials is carried out in leaves properly collected, washed, dried and homogenized [2]. The homogenized samples are frequently acid digested [3] for further analysis by inductively coupled plasma optical emission spectroscopy (ICP OES), flame atomic absorption spectrometry (FAAS), inductively coupled plasma mass spectrometry (ICP-MS) [4][5][6][7] or by using other analytical methods [8]. ...
... This is especially true for vegetables that are in direct contact with pollutants present in the soil and in the air. Several works have used LIBS to analyze trace elements in plants (Sun et al. 1999;Assion et al. 2003;Trevizan et al. 2009), and in particular in leaves (Samek et al. 2006;Myriam et al. 2007;Miloslav et al. 2009). ...
... Among them laser-induced breakdown spectroscopy (LIBS) is an analytical detection technique based on atomic emission spectroscopy to measure elemental composition. With the development of laser and detection systems, LIBS has been applied in various fields, including combustion, metallurgy, foods and human [3][4][5][6], etc. Especially, the advantages of the method are its applicability to various fields such as combustion, metallurgy, and the harsh environment. However, LIBS applicability cannot reach the trace species detection needs because of its detection limit. ...
Since the demands for lowering the burdens on the environment will continue to grow steadily, understanding of pollutant emission characteristics becomes more and more important to minimize environmental disruption. These pollutant emission conditions cannot be estimated in real-time using conventional mass-based methods because of their low concentrations in air or exhaust gases. Therefore, new evaluation criteria are required for better understanding of their characteristics. In this study, the laser breakdown time-of-flight mass spectrometry was developed and applied to hydrocarbons to detect the elemental composition of gas phase materials. The laser wavelength dependence of this method was evaluated using 1064 and 266 nm laser outputs. Signals from fragments of hydrocarbons appeared using 266 nm. On the other hand, it was found that the mass spectra of atoms can be detected using the 1064 nm laser breakdown process without intermediate fragment signals. This feature is important to detect atomic signals of the measured materials without the interference of fragmentations. The pressure effect was also evaluated to enhance the detection limit. The higher pressure tends to induce the higher atomic signals. The detection limit can easily reach to ppb or less. The signal intensity was proportional to the concentration of hydrocarbons introduced. The method was applied to various hydrocarbons and the breakdown characteristics of these molecules were taken for the quantitative analysis. Compared with conventional measurements, this method has a lot of merits of the simple signal analysis, real-time and sensitive detection features. The method can cover various industrial applications including the exhaust analysis of combustors, environmental monitoring of air, and plant monitoring for safety and security.
... Laser-induced breakdown spectroscopy (LIBS) is an analytical detection technique based on atomic emission spectroscopy to measure elemental composition. With the development of laser and detection systems, LIBS has been applied in various fields, including combustion, metallurgy, foods and human [11][12][13][14], etc. Especially, the advantages of the method are more significant in the areas of combustion, metallurgy, and the harsh environment. However, LIBS applicability cannot reach the trace species detection needs because of its detection limit. ...
It has been highly recognized heavy metals pollution concerns the environment, as well as human health. Mercury (Hg) pollution has greatly increased and been considered as a global pollutant because of its long residence time in surrounding. This paper describes the rapid detection of mercury using laser breakdown time-of-flight mass spectrometry at high sensitivity without fragmentation interference from other species. Two irradiation wavelengths 1064 nm and 532 nm were employed under various experimental conditions. The second harmonic 532 nm performs excellent measurement results. The influence of pressure on mercury signal intensity displays a liner growth when increasing the pressure. These results also show as the laser power increased, nitrogen signal intensity increased, but mercury signal intensity increased first and then decreased. Experiment with different buffer gases clarified the recombination of Hg ions and electrons when increasing the laser power, resulting in the decrease of mercury signal intensity. According to these measurement results, the method of enlarging focus area and reducing laser power by tilting the focus lens was applied to decrease the recombination rate to enhance the detection limit. It is demonstrated that the detection limit with 1ppb can be acquired facilely.
... It is however still a challenging task to apply the LIBS technique, traditionally and commonly used for inorganic sample analysis (alloys, minerals…), for vegetable or more generally for food analysis [9]. Several works have used LIBS to analyze trace elements in plants101112, and in particular in leaves131415. In our previous work, we have demonstrated the sensitive detection of a large number of trace or ultra-trace elements in fresh vegetables using LIBS [16]. ...
Optical emission of laser-induced plasma on the surface of fresh vegetables provides sensitive analysis of trace elements for in situ or online detection of these materials. This emergent technique promises applications with expected outcomes in food security or nutrition quality, as well as environment pollution detection. Characterization of the plasma induced on such soft and humid materials represents the first step towards quantitative measurement using this technique. In this paper, we present the experimental setup and protocol that optimize the plasma generation on fresh vegetables, potatoes for instance. The temporal evolution of the plasma properties are investigated using time-resolved laser-induced breakdown spectroscopy (LIBS). In particular, the electron density and the temperatures of the plasma are reported as functions of its decay time. The temperatures are evaluated from the well known Boltzmann and Saha-Boltzmann plot methods. These temperatures are further compared to that of the typical molecular species, CN, for laser-induced plasma from plant materials. This comparison validates the local thermodynamic equilibrium (LTE) in the specific case of fresh vegetables ablated in the typical LIBS conditions. A study of the temporal evolution of the signal to noise ratio also provides practical indications for an optimized detection of trace elements. We demonstrate finally that, under certain conditions, the calibration-free LIBS procedure can be applied to determine the concentrations of trace elements in fresh vegetables.
... Pouzar et al. [42] proposed a method for the determination of K, P, Mg and Ca in plants leaves. Seven samples of barley and three samples of poppy were used as standards. ...
Developments and contributions of laser-induced breakdown spectroscopy (LIBS) for the determination of elements in plant materials are reviewed. Several applications where the solid samples are interrogated by simply focusing the laser pulses directly onto a fresh or dried surface of leaves, roots, fruits, vegetables, wood and pollen are presented. For quantitative purposes aiming at plant nutrition diagnosis, the test sample presentation in the form of pressed pellets, prepared from clean, dried and properly ground/homogenized leaves, and the use of univariate or multivariate calibration strategies are revisited.
... Lidiane [5] and other partners used LIBS to analyse the leaf by neuro-genetic approach. Miloslav [6] and his partners analysed the crop leaves and detected six certified reference materials of leaf tissues by LIBS. ...
Laser-Induced Breakdown Spectroscopy (LIBS) is a new way to analyze the plant ecology. The experimental used a Q-switched Nd:YAG laser to be the laser source and equipped with an eight-channel model spectrometer which's wavelength range between 200 and 1100 nm. Studying the spectrum of the air-drying leaves and the nature leaves and detected the elements which contain Fe, Ca, Na, Mg, K, Cu, Al and Mn. Displaying the list which shows the all spectrum and elements. Refer to Fe as the benchmark, obtain the relative content of trace elements. At the same time, this technology can be employed for food safety and environment pollution evaluation. It will be the based for studying the portable LIBS instrument of detecting the pollution of heavy metal. © 2012 IFIP International Federation for Information Processing.
... Very recently, LIBS technique was applied to breakfast cereals for the determination of calcium concentration using the calibration curve method with a validation by ICP-AES [30]. Some recent works report the direct comparison between ICP-AES and LIBS for analysis of organic samples such as plants [31,32]. Comparing the analytical performances of these different techniques for the quantitative analysis of mineral elements in milk powders is also the motivation of the present work. ...
Mineral elements contained in commercially available milk powders, including seven infant formulae and one adult milk, were analyzed with inductively coupled plasma atomic emission spectrometry (ICP-AES) and laser-induced breakdown spectroscopy (LIBS). The purpose of this work was, through a direct comparison of the analytical results, to provide an assessment of the performance of LIBS, and especially of the procedure of calibration-free LIBS (CF-LIBS), to deal with organic compounds such as milk powders. In our experiments, the matrix effect was clearly observed affecting the analytical results each time laser ablation was employed for sampling. Such effect was in addition directly observed by determining the physical parameters of the plasmas induced on the different samples. The CF-LIBS procedure was implemented to deduce the concentrations of Mg and K with Ca as the internal reference element. Quantitative analytical results with CF-LIBS were validated with ICP-AES measurements and nominal concentrations specified for commercial milks. The obtained good results with the CF-LIBS procedure demonstrate its capacity to take into account the difference in physical parameters of the plasma in the calculation of the concentrations of mineral elements, which allows a significant reduction of the matrix effect related to laser ablation. We finally discuss the way to optimize the implementation of the CF-LIBS procedure for the analysis of mineral elements in organic materials.
Impact of laser spot dimensions on laser induced breakdown spectroscopy (LIBS) analysis of heterogeneous samples has been studied in details. The study was stimulated by comparing analytical performance of three...
Maerua oblongifolia is a traditional medicinal plant served for health advancing effects due to rich nutrients. The compositional analysis of this plant was carried out using the calibration-free laser-induced breakdown spectroscopy (CF-LIBS). The laser-produced plasma was generated on the pelletized samples of roots, stem, leaves, and fruits to record and analyze the corresponding emission spectra. The spectroscopic analysis revealed the presence of elements such as Na, Ca, Mg, K, Al, Fe, Li, Si, Sr, Zn, Ba, and Rb. As a prerequisite of quantitative analysis, and for the determination of reliable plasma parameters, a simplified approach was used to correct the self-absorption in the emission lines to determine the plasma temperature using Boltzmann and Saha-Boltzmann plot methods. This procedure was further used to develop the modified Saha-Boltzmann plot, which uses the columnar densities of emitting species at the ground state to determine the plasma temperature. Finally, the one-line CF-LIBS was used to quantify the concentration of all the perceived constituent elements. LIBS results were cross-validated with that obtained from ICP-MS.
The rapid determination of cadmium in solid rice and wheat samples was carried out using plasma jet spectroscopy. This technology is based on the atomic emission spectrometry (AES) with a plasma jet (PJ-AES). The performance of PJ-AES for the determination of Cd in rice and wheat samples was systematically investigated, including the linear range and sensitivity. The linear regression relationships for Cd in rice and wheat were y = 7659.496x + 4933.642 with R² = 0.987 and y = 10844.734x + 7815.255 with R² = 0.984, respectively. The linear range was from 0.03 to 1.28 mg/kg. The detection limits were 0.0071 and 0.0078 mg/kg. This method has the advantages of speed, which is reflected in its sample preparation time of only 7.5 min, while the preparation times for AAS and ICP-MS are 3 and 2 h. The developed method offers simple sample processing, small size, low cost, and accurate analysis, while being economical and efficient.
Precision agriculture aims to increase yield and profits while reducing costs, waste, and environmental side-effects. This is achieved through a process of measuring, modelling and acting; for example, laser-induced breakdown spectroscopy (LIBS) can be used to measure macro and micro nutrients in crops to determine nutrient requirements. The limiting factor with quantitative LIBS analysis of plant nutrient levels is the variation between shots on the same sample. Following a review of current literature relevant to LIBS for agriculture, this work investigates whether different chemometric methods can mitigate these variations and can create quantitative calibrations for nutrient levels in fresh and dried pelletised pasture under laboratory conditions. The methods explored were Savitzky Golay filtering, multiple linear regression, principal component regression, partial least-squares regression, gaussian process regression, and artificial neural networks. The algorithms that performed best were partial least-squares with gaussian process regression (R² of 0.93, 0.95, and 0.92 for K, Na, and Mn, respectively), principal components analysis with artificial neural networks (R² of 0.94, 0.83, and 0.80 for Fe, Ca, and Mg, respectively), and partial least-squares with artificial neural networks (R² of 0.77 for B). Removing the moisture from the pasture improved model R² values by 4–5% on average. Acquiring spectra under an argon purge produced a small reduction in accuracy for some nutrients compared to models acquired in air. Including categorical data in the principal component regression and the artificial neural networks produced negligible improvements in prediction. This chapter will give an introduction of using different types of chemometric analyses on spectra generated by LIBS to measure micro and macro nutrients in pasture under laboratory conditions. It discusses the challenges faced when building models for each nutrient.
The ability to provide a fast and multielemental analytical response directly from a solid sample makes both laser-induced breakdown spectroscopy (LIBS) and X-ray fluorescence spectrometry (XRF) very versatile tools for plant nutrition diagnosis. This review focuses on the main developments and advances in LIBS and XRF in the analysis of plant materials over the last ten years. Fundamental aspects and instrumentation are given for both techniques. The developments in the quantitative analysis of plant leaves are discussed, with special emphasis on the key aspects and challenges concerning field sampling protocols, sample preparation, and calibration strategies. Microchemical imaging applications by LIBS and XRF (including synchrotron radiation) are also presented in a broader selection of plant compartments (e.g., leaves, roots, stems, and seeds). Challenges, expectations and complementarities of LIBS and XRF towards plant nutrition diagnosis are thoroughly discussed.
In this study, Nd:YAG laser pulse is used to ablate the Magnesium sample for laser induced breakdown spectroscopyanalysis. The emission lines are plotted for ionic and atomic element of Mg I and Mg II respectively. The emission lines of Mg I and Mg II were recorded at wavelength of 279.55 nm, 280.27 nm and 285.21 nm. The analysis including the different of gate delay, determination of signal to background ratio and calibration curve of different concentration of magnesium is discussed in details.
Laser-induced breakdown spectroscopy (LIBS) is a technique increasingly used to perform fast semi-quantitative
multi-elemental analyses of various materials without any complex sample preparation, being also suitable
for in situ analyses. Few studies have been performed to understand the influence of laser wavelength on LIBS analytical performance on environmental samples. The main goal of this study was to perform a comparative elemental analysis of a number of soils, citrus leaves, and synthetic solid matrices using two different wavelengths, i.e., 532 and 1064 nm of Nd:YAG lasers, and a spectrometer coupled to a non-intensified charge-coupled device camera as the detection system. The emission lines with higher upper energy level, i.e., C I—193.03 (7.685 eV) and Si I—212.41 nm (6.616 eV), were more intense when using the 532 nm than the 1064 nm laser light, whereas the opposite occurred for elements with lower upper energy level, i.e., Ti I—336.12 nm (3.716 eV) and Fe I—368.75 nm (4.220 eV). The observed increase in LIBS signal between the two wavelengths is about 30–50%. The relationship between the line emission intensities and the used excitation wavelengths were associated to the upper level energy of the element.
Laser-induced breakdown spectroscopy (LIBS) is becoming a rapid and easy technique for quantitative elemental analysis. However, the implementation of accurate quantitative LIBS analysis is always subject to noise interference. In this work, in order to improve LIBS analysis performance for trace elements in aluminium alloys, a modified trade-off soft and hard threshold method is proposed based on the wavelet theory, where optimal parameters are deduced to eliminate noise interference. By using the modified algorithm combined with an Al I line at 308.215 nm as an internal standard, the statistical parameters including the determination coefficient (R²), the root mean square error (RMSE) and the relative standard deviation (RSD) of magnesium (Mg), manganese (Mn) and cuprum (Cu) in aluminium alloys are all significantly improved. The most significant improvement of R² is 0.066 for Cu. The maximum RMSE reduction value is 0.583 for Mg, and the mean value of RMSE reduction is 0.261 for all three trace elements. And after de-noising, the value of RSD gets smaller for each trace element. Such results indicate that the optimized algorithm is valid for the effective improvement of the accuracy of quantitative LIBS analysis in the trace element determination of aluminium alloys.
Toxic metal contamination and nutritious elements detection are two main issues in agriculture, as these relate to the development of agriculture and human health. Among the investigated techniques, laser-induced breakdown spectroscopy (LIBS) has the potential to become a fast and effective analytical tool for the application in agriculture. Herein is a review of the recent developments and applications of LIBS in the field of agriculture. We discussed the LIBS instruments and quantitative analytical methods, and introduced signal enhancement methods for expanding the elements detection capability. For detailed aspects of applications, we reviewed the recent progress in soil, plants, agricultural products and food. To solve the severe “matrix effect” problem and to meet high demands in agriculture, we recommended the development of robust and practical LIBS instruments, exploiting the chemometric methods and signal enhancement methods for quantitative analysis.
A rapid high throughput non-destructive method, using an X-ray microprobe beamline (Very Sensitive Elemental and Structural Probe Employing Radiation from Synchrotron, VESPERS, CLS Saskatoon), has been developed to screen multiple minerals in cereal and pulse meals. Starch spiked with commercial mineral standards cocktail at different concentrations was optimized to develop standard curve to determine mineral concentrations in grain meal samples. A grid sample holder to hold 84 samples was built for high precision and rapid analysis of multiple samples. The developed analytical method can be used for quantitative determination of eleven minerals including Ca, Cr, Mn, Fe, Ni, Co, Cu, Zn, Se, Rb and Mo at mg Kg− 1 or ppm concentrations. Method adaptability was assessed using a cereal crop wheat and pulse crop chickpea grain meal. The method was successfully used for Ca, Mn, Fe, Ni, Cu, Zn, Se, Rb and Mo determination in wheat and chickpea and measurements were cross analyzed using Inductively Coupled Plasma Mass Spectroscopy ICP-MS technique for the same samples. The method is highly sensitive (sensitivity at ppm level) and can be adapted to analyze mineral concentrations in grain meal from crops of interest. The precise and reproducible high throughput screening method can be used in crop improvement to develop bio-fortified grains with increased mineral concentrations.
The development of a multivariate model for fiber content prediction in sugar cane has been investigated and can be offered as an alternative to the wet methods of analysis. The importance of fiber in bagasse of sugar cane is directly linked to the production of sugar and alcohol performances and to payment systems. The analytical method investigated here was the Laser-Induced Breakdown Spectroscopy (LIBS) combined with a Partial Least Squares (PLS) chemometric tool that can achieve the best model to predict fiber content in sugar cane. A total of 6287 spectra of raw samples of sugar cane bagasse was evaluated. The optimum conditions of operation of the equipment for the acquisition of the most sensitive LIBS signals were tested through Design of Experiments (DOE).
Microsampling strategies were evaluated for the direct analysis of dried sugar cane leaves by energy-dispersive X-ray fluorescence spectrometry (EDXRF) and laser-induced breakdown spectroscopy (LIBS). The analysis by EDXRF was carried out by irradiating each leaf fragment in its middle portion with a collimated 5 mm X-ray spot size during 50 s, allowing the determination of P, K, Ca, S, Fe, Mn and Si. EDXRF was also useful to conclude that 15 leaf fragments (37.5 % of the recommended sampling area) were enough for attaining a representative analytical response from the whole diagnostic leaf. Regarding LIBS, that employs a substantial smaller ablation area (i.e., 750 µm laser spot size), sampling strategies were defined by taking into account the microchemical distribution of P, Ca, Mg, Fe, Mn, B and Si in 9 mm x 9 mm leaf fragment area. The proposed sampling protocol relied on the interrogation (rastering) of 3 equally spaced sampling lines in each leaf fragment with 48 accumulated laser pulses per line (Nd:YAG at 1064 nm, 5 ns, 10 Hz, 50 J cm-2) perpendicularly to the leaf midrib. This strategy enabled the simultaneous determination of P, K, Ca, Mg, Fe, Cu, Mn, Zn, B and Si by LIBS. Cross-validation between LIBS and EDXRF for P, K, Ca, Fe, Mn and Si predicted mass fractions presented high linear correlation coefficients of up to 0.9778 (selecting 15 leaf fragments per diagnostic leaf from 10 different sugar cane varieties). Results provide insights into a novel and promising strategy for direct and fast plant nutrition diagnosis, fostering further studies for in situ analysis of fresh leaves, strengthening the implementation of Precision Agriculture and Green Chemistry concepts.
The emission of trace heavy metals, such as mercury (Hg), from power plants and other industries is a severe environmental problem concerning the public health. The laser-induced plasma technique was employed to measure Hg under various conditions, which reveals several merits of this method at low pressure. The main interferences of laser-induced breakdown spectroscopy (LIBS), which include the black-body-like emission from plasma itself and coexisting molecular and atomic emissions, decreased significantly using low pressure laser-induced plasma. Under low pressure conditions, Hg signal was rather clear without serious influence even if there is no delay time from the laser irradiation, which means the gated detection device is not necessary. This method featured the detection limit of 0.3 ppm at pressure 700 Pa. Additionally, the feasible of this method in real applications was demonstrated by measuring Hg in combustion gas which performed preferable results. (C) 2013 The Japan Society of Applied Physics
Laser-induced breakdown spectroscopy (LIBS) technique has been applied to inves-
tigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software.
LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identi¯cation and discrimination of di®erent types of bacteria.
Laser-induced breakdown spectroscopy (LIBS) technology is an appealing technique compared with many other types of elemental analysis because of the fast response, high sensitivity, real-time, and noncontact features. One of the challenging targets of LIBS is the enhancement of the detection limit. In this study, the detection limit of gas-phase LIBS analysis has been improved by controlling the pressure and laser pulse width. In order to verify this method, low-pressure gas plasma was induced using nanosecond and picosecond lasers. The method was applied to the detection of Hg. The emission intensity ratio of the Hg atom to NO (IHg/INO) was analyzed to evaluate the LIBS detection limit because the NO emission (interference signal) was formed during the plasma generation and cooling process of N2 and O2 in the air. It was demonstrated that the enhancement of IHg/INO arose by decreasing the pressure to a few kilopascals, and the IHg/INO of the picosecond breakdown was always much higher than that of the nanosecond breakdown at low buffer gas pressure. Enhancement of IHg/INO increased more than 10 times at 700 Pa using picosecond laser with 35 ps pulse width. The detection limit was enhanced to 0.03 ppm (parts per million). We also saw that the spectra from the center and edge parts of plasma showed different features. Comparing the central spectra with the edge spectra, IHg/INO of the edge spectra was higher than that of the central spectra using the picosecond laser breakdown process.
This is the twenty-fifth annual review published in JAAS on the application of atomic spectrometry to the chemical analysis of environmental samples. This Update refers to papers published approximately between September 2008 and August 2009. In the analysis of air, work has focused on: the need to collect and characterise ultrafines; determination of elements such as Be, Hg and PGEs in air samples; application of SRXRF techniques and advances in the development of field deployable aerosol mass spectrometry systems. In the analysis of water, significant areas of activity currently focus on elemental speciation of As, Cr, Hg and Sn. Work in increasing method sensitivities through the use of vapour generation and optimization of extraction and preconcentration procedures continues. The increased global awareness of the need to monitor levels of potentially toxic elements (PTE) in soils is desirable and this is reflected in a growing body of published literature from authors in the Middle East, Asia and Africa. However, a potential criticism of some studies is that they simply report the concentrations of analytes in particular soils or plants, without providing sufficient information on analytical quality control and with little assessment of their environmental significance, e.g. those levels that are a threat to human health. In the field of geological analysis, considerable effort is being spent not only on the production, characterization and certification of new geological reference materials, but also on enhancing the certification of existing reference materials and the development of reference materials with assigned elemental isotopic ratios. Laser ablation continues to go from strength to strength in being adopted as a solid sampling tool in geochemical analysis. Feedback on this review is most welcome and the lead author can be contacted using the email address provided.
In this paper, the capabilities of laser-induced breakdown spectroscopy (LIBS) for rapid analysis to multi-component plant are illustrated using a 1064 nm laser focused onto the surface of folium lycii. Based on homogeneous plasma assumption, nine of essential micronutrients in folium lycii are identified. Using Saha equation and Boltzmann plot method electron density and plasma temperature are obtained, and their relative concentration (Ca, Mg, Al, Si, Ti, Na, K, Li, and Sr) are obtained employing a semi-quantitative method.
Laser induced breakdownspectrometry (LIBS) was applied for the determination of macro (P, K, Ca, Mg) and micronutrients (B, Cu, Fe, Mn and Zn) in sugar cane leaves, which is one of the most economically important crops in Brazil. Operational conditions were previously optimized by a neuro-genetic approach, by using a laser Nd:YAG at 1064 nm with 110 mJ per pulse focused on a pellet surface prepared with ground plant samples. Emission intensities were measured after 2.0 μs delay time, with 4.5 μs integration time gate and 25 accumulated laser pulses. Measurements of LIBS spectra were based on triplicate and each replicate consisted of an average of ten spectra collected in different sites (craters) of the pellet. Quantitative determinations were carried out by using univariate calibration and chemometric methods, such as PLSR and iPLS. The calibration models were obtained by using 26 laboratory samples and the validation was carried out by using 15 test samples. For comparative purpose, these samples were also microwave-assisted digested and further analyzed by ICP OES. In general, most results obtained by LIBS did not differ significantly from ICP OES data by applying a t-test at 95% confidence level. Both LIBS multivariate and univariate calibration methods produced similar results, except for Fe where better results were achieved by the multivariate approach. Repeatability precision varied from 0.7 to 15% and 1.3 to 20% from measurements obtained by multivariate and univariate calibration, respectively. It is demonstrated that LIBS is a powerful tool for analysis of pellets of plant materials for determination of macro and micronutrients by choosing calibration and validation samples with similar matrix composition.
A review article on laser-induced breakdown spectroscopy is presented. It focuses on developments in LIBS over the years 2008 - 2012. After introducing the general information sources of LIBS, the paper discusses the advancement in the understanding of fundamental principles of LIBS and the excitation strategies based on dual and multipulse schemes, resonant LIBS and ultrafast lasers. Approaches to the analysis of distant objects follow. Applications are presented based on a broad selection of new areas of research and innovative uses of LIBS. Conclusions and Outlook briefly summarizes recent advances and provides a prospective of short term developments in LIBS.
This is the second iteration of this review covering developments in 'Atomic Spectrometry'. It covers atomic emission, absorption, fluorescence and mass spectrometry, but excludes material on speciation and coupled techniques which is included in a separate review.(1) It should be read in conjunction with the other related reviews in the series.(2-5) A critical approach to the selection of material has been adopted, with only novel developments in instrumentation, techniques and methodology being included. Most techniques have reached a level of maturity which precludes the emergence of 'stand-out' new developments. It is noteworthy that there are very few novel publications in sections on chemometrics, fundamental studies, or direct solids analysis. Sample introduction continues to generate a steady stream of research outputs, but these are mainly derivative and focused on applications. The advent of SF-ICP-MS is becoming widely adopted as a reliable technique for IR measurements, so this had been the main growth area. Likewise, the use of femtosecond UV lasers has now entered the mainstream for geological applications.
The recent progress made in developing laser-induced breakdown spectroscopy (LIBS) has transformed LIBS from an elemental analysis technique to one that can be applied for the reagentless analysis of molecularly complex biological materials or clinical specimens. Rapid advances in the LIBS technology have spawned a growing number of recently published articles in peer-reviewed journals which have consistently demonstrated the capability of LIBS to rapidly detect, biochemically characterize and analyse, and/or accurately identify various biological, biomedical or clinical samples. These analyses are inherently real-time, require no sample preparation, and offer high sensitivity and specificity. This overview of the biomedical applications of LIBS is meant to summarize the research that has been performed to date, as well as to suggest to health care providers several possible specific future applications which, if successfully implemented, would be significantly beneficial to humankind.
It has been demonstrated that laser induced breakdown spectrometry (LIBS) can be used as an alternative method for the determination of macro (P, K, Ca, Mg) and micronutrients (B, Fe, Cu, Mn, Zn) in pellets of plant materials. However, information is required regarding the sample preparation for plant analysis by LIBS. In this work, methods involving cryogenic grinding and planetary ball milling were evaluated for leaves comminution before pellets preparation. The particle sizes were associated to chemical sample properties such as fiber and cellulose contents, as well as to pellets porosity and density. The pellets were ablated at 30 different sites by applying 25 laser pulses per site (Nd:YAG@1064 nm, 5 ns, 10 Hz, 25J cm(-2)). The plasma emission collected by lenses was directed through an optical fiber towards a high resolution echelle spectrometer equipped with an ICCD. Delay time and integration time gate were fixed at 2.0 and 4.5 μs, respectively. Experiments carried out with pellets of sugarcane, orange tree and soy leaves showed a significant effect of the plant species for choosing the most appropriate grinding conditions. By using ball milling with agate materials, 20 min grinding for orange tree and soy, and 60 min for sugarcane leaves led to particle size distributions generally lower than 75 μm. Cryogenic grinding yielded similar particle size distributions after 10 min for orange tree, 20 min for soy and 30 min for sugarcane leaves. There was up to 50% emission signal enhancement on LIBS measurements for most elements by improving particle size distribution and consequently the pellet porosity.
In this paper we investigate the effect that adverse environmental and metabolic stresses have on the laser-induced breakdown spectroscopy (LIBS) identification of bacterial specimens. Single-pulse LIBS spectra were acquired from a non-pathogenic strain of Escherichia coli cultured in two different nutrient media: a trypticase soy agar and a MacConkey agar with a 0.01% concentration of deoxycholate. A chemometric discriminant function analysis showed that the LIBS spectra acquired from bacteria grown in these two media were indistinguishable and easily discriminated from spectra acquired from two other non-pathogenic E. coli strains. LIBS spectra were obtained from specimens of a nonpathogenic E. coli strain and an avirulent derivative of the pathogen Streptococcus viridans in three different metabolic situations: live bacteria reproducing in the log-phase, bacteria inactivated on an abiotic surface by exposure to bactericidal ultraviolet irradiation, and bacteria killed via autoclaving. All bacteria were correctly identified regardless of their metabolic state. This successful identification suggests the possibility of testing specimens that have been rendered safe for handling prior to LIBS identification. This would greatly enhance personnel safety and lower the cost of a LIBS-based diagnostic test. LIBS spectra were obtained from pathogenic and non-pathogenic bacteria that were deprived of nutrition for a period of time ranging from one day to nine days by deposition on an abiotic surface at room temperature. All specimens were successfully classified by species regardless of the duration of nutrient deprivation.
Results are presented for analyzing the composition of various materials (both conducting and non-conducting) obtained in an atomic-emission spectrometer with a laser source for spectrum excitation. The possibility is confirmed of using a laser analyzer LEA S 500 in metallurgy and the refractory industry.
This review covers a relatively mature area of atomic spectrometry, hence there are fewer new developments than in other research fields. The review should be read in conjunction with the previous year’s review and with other related reviews in the series. Over the last several years the research emphasis has shifted from novel developments to more routine applications. A plethora of methods have been developed for the preconcentration and separation of analyte and matrix prior to sample introduction. Some novel fundamental studies of plasmas have been published, and new research in the area of laser induced breakdown spectroscopy is still appearing, perhaps reflecting the status of a technique which is always on the verge of “arriving” in the mainstream. The flurry of activity generated by the widespread commercialisation of simultaneous solid-state atomic emission detectors has diminished, particularly for chemometrics and transient signal analysis. The only other major area of novelty is that of speciation analysis using coupled techniques, and even this has moved towards more routine applications.
This article reports on the utilization of X-ray microradiography and laser induced breakdown spectroscopy (LIBS) techniques for investigation of the metal accumulation in different part of leaf samples. The potential of the LIBS-analysis for finding the proper plant species for phytoremediation is compared with the results of microradiography measurements at the HERCULES source at ENEA, Rome (Italy) and X-ray microradiography experiments at the ELETTRA Synchrotron, Trieste (Italy). Microsc. Res. Tech., 2007. © 2006 Wiley-Liss, Inc.
We report on the development and implementation of analytical methodology for investigating elemental accumulation in different layers within plant leaves, with in-situ spatial resolution mapping, exploiting the technique of LIBS. The spectrochemical analysis of lead-doped leaf samples is demonstrated to develop a real time identification procedure in order to complement other analytical techniques not lending themselves for spatial resolution analysis. Our findings suggest that with elevated levels of Pb within the plants transportation and storage of some nutrition elements is changed.
Laser induced breakdown spectroscopy (LIBS) has become an analytical tool for the direct analysis of a large variety of materials in order to provide qualitative and/or quantitative information. However, there is a lack of information for LIBS analysis of agricultural and environmental samples. In this work a LIBS system has been evaluated for the determination of macronutrients (P, K, Ca, Mg) in pellets of vegetal reference materials. An experimental setup was designed by using a Nd:YAG laser operating at 1064 nm and an Echelle spectrometer with ICCD detector. The plasma temperature was estimated by Boltzmann plots and instrumental parameters such as delay time, lens-to-sample distance and pulse energy were evaluated. Certified reference materials as well as reference materials were used for analytical calibrations of P, K, Ca, and Mg. Most results of the direct analysis of plant samples by LIBS were in reasonable agreement with those obtained by ICP OES after wet acid decomposition.
- E H Evans
- J A Day
- Ch
- W J Palmer
- C M M Price
- J F Smith
- Tyson
E. H. Evans, J. A. Day, Ch. Palmer, W. J. Price, C. M. M. Smith and
J. F. Tyson, J. Anal. At. Spectrom., 2007, 22, 663-696.
- Q Sun
- M Tran
- B W Smith
- J D Winefordner
Q. Sun, M. Tran, B. W. Smith and J. D. Winefordner, Can. J. Anal.
Sci. Spectrosc., 1999, 44, 164-170.
- J Kaiser
J. Kaiser et al., Microsc. Res. Tech., 2007, 70, 147-153.
- V D Kopachevskii
- M A Krivosheeva
V. D. Kopachevskii and M. A. Krivosheeva, Refract. Ind. Ceram.,
2007, 48(4), 255-258.
- M Galiov
M. Galiov a et al., Spectrochim. Acta, Part B, 2007, 62, 1597-1605.
- Evans