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The Use of Solid Bonded-phase Extraction as Alternative to Liquid–Liquid Partitioning for Pesticide Residue Analysis of Crops
Abstract
The application of solid bonded-phase extraction to the cleanup of sample extracts in residue analysis has been examined. In comparison with liquid-liquid partition the following advantages are offered: the consumption of solvent is considerably reduced, these are less interferences, and accuracy and precision are improved.
... Solid bondedphase extraction and gas chromatography (GC) were used to detect oxadiazon residues in crops. When extracted with acetonitrile/water (8/2, v/v), the average recovery was 97% (3). The oxadiazon residues in sediment samples were detected by GC mass spectrometry (GC-MS) in San Diego Creek, CA, USA (4). ...
Rapid and simple methods for the determination of Jiahuangxianjunzuo (JHXJZ) in paddy water, brown rice, soil and rice straw was developed and validated. This method involved the use of ultrahigh-performance liquid chromatography equipped with photodiode array detector. The most important factor was chromatographic conditions, as identified through an orthogonal experimental design. This method showed good recoveries and precisions, thereby indicating its suitability for monitoring of JHXJZ residues in paddy water, brown rice, soil and rice straw. Furthermore, hydrolysis experiment was conducted in the laboratory under pH = 7 buffer solutions, and its degradation product was identified as 2-(4-fluorophenyl)-5-methoxy-1,3,4-oxadiazole by high-resolution mass spectrometry. JHXJZ has a major degradation pathway in the water which the OH- nucleophilic attack the C5 of 1,3,4-oxadiazole ring. Then it leaves mesyl to form intermediate 5-(4-fluorophenyl)-1,3,4-oxadiazol-2-ol and the intermediate combined with methanol formed the degradation product 2-(4-fluorophenyl)-5-methoxy-1,3,4-oxadiazole by the loss of one H2O.The degradation pathways of JHXJZ under the present indoor simulation conditions were proposed.
... SPE was developed as a substitute for classical LL partitioning to reduce the consumption of hazardous chlorinated solvents in the partitioning step [44]. Despite using the SPE instead of LL partitioning, the method still requires a large glass column with large volumes of solvent for washing and eluting. ...
Quick, easy, cheap, effective, rugged, and safe sample preparation approach for pesticide residue analysis using traditional detectors in chromatography: A review In pesticide residue analysis, relatively low-sensitivity traditional detectors, such as UV, diode array, electron-capture, flame photometric, and nitrogen-phosphorus detectors, have been used following classical sample preparation (liquid-liquid extraction and open glass column cleanup); however, the extraction method is laborious, time-consuming, and requires large volumes of toxic organic solvents. A quick, easy, cheap, effective, rugged, and safe method was introduced in 2003 and coupled with selective and sensitive mass detectors to overcome the aforementioned drawbacks. Compared to traditional detectors, mass spectrometers are still far more expensive and not available in most modestly equipped laboratories, owing to maintenance and cost-related issues. Even available, traditional detectors are still being used for analysis of residues in agricultural commodities. It is widely known that the quick, easy, cheap, effective, rugged, and safe method is incompatible with conventional detectors owing to matrix complexity and low sensitivity. Therefore, modifications using column/cartridge-based solid-phase extraction instead of dispersive solid-phase extraction for cleanup have been applied in most cases to compensate and enable the adaptation of the extraction method to conventional detectors. In gas chromatography, the matrix enhancement effect of some analytes has been observed, which lowers the limit of detection and, therefore, enables gas chromatography to be compatible with the quick, easy, cheap, effective, rugged, and safe extraction method. For liquid chromatography with a UV detector, a combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction was found to reduce the matrix interference and increase the sensitivity. A suitable double-layer column/cartridge-based solid-phase extraction might be the perfect solution, instead of a time-consuming combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction. Therefore, replacing dispersive solid-phase extraction with column/cartridge-based solid-phase extraction in the cleanup step can make the quick, easy, cheap, effective, rugged, and safe extraction method compatible with traditional detectors for more sensitive, effective, and green analysis.
... In the past decades, oxadiazon was usually determined by high performance liquid chromatography (HPLC) [18], gas chromatography with electron capture detector (GC-ECD) [19][20][21][22], or gas chromatography with mass spectrometry (GC-MS) [23][24][25][26][27]. When chromatographic methods are used, sample pretreatments are often crucial for the whole chromatographic analysis, traditional oxadiazon analysis procedures are like that: solid bondedphase extraction [28], and liquid-liquid extraction [29]. Although satisfactory recoveries have been received in these traditional methods, these traditional sample procedures are time-consuming, labor-intensive, complicated, and expensive; moreover, they produce considerable quantities of wastes, and frequently, a sufficiently low limit of detection is unobtainable [30]. ...
A fast and sensitive analytical method for the determination of jiahuangxianjunzuo (JHXJZ) using gas chromatography equipped with nitrogen–phosphorus detector was developed and validated for the analysis of Goji berry which is grown in Qinghai Plateau of China. This method employs modified QuEChERS followed by detection. JHXJZ was extracted by alkaline acetonitrile [containing 1% (v/v) NH3·H2O] and partitioned with a mixture of NaCl and Mg2SO4, and then cleanup was done with 30 mg GCB and 100 mg MgSO4. With this modified QuEChERS procedure, the linearity over a concentration range 0.01–5 μg mL⁻¹ was good with a correlation coefficient (r) > 0.9999. Recovery at three different fortification levels was 90.40–100.9%, respectively, with a relative standard deviation < 5% for all analytes. The limits of detection and the limits of quantification were 0.003 and 0.01 mg kg⁻¹, respectively. JHXJZ was detected on three Goji berry food products; all positive samples showed JHXJZ contents below the legal limit established by the EU for other analogous berry-based products. These results can be used to help establish appropriate application frequencies and harvest intervals for JHXJZ on Goji berry.
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... SPE was developed as a substitute for classical LL partitioning to reduce the consumption of hazardous chlorinated solvents in the partitioning step [44]. Despite using the SPE instead of LL partitioning, the method still requires a large glass column with large volumes of solvent for washing and eluting. ...
... SPE was developed as a substitute for classical LL partitioning to reduce the consumption of hazardous chlorinated solvents in the partitioning step [44]. Despite using the SPE instead of LL partitioning, the method still requires a large glass column with large volumes of solvent for washing and eluting. ...
In pesticide residue analysis, relatively low-sensitivity traditional detectors, such as UV, diode array, electron-capture, flame photometric, and nitrogen-phosphorus detectors, have been used following classical sample preparation (liquid–liquid extraction and open glass column cleanup); however, the extraction method is laborious, time-consuming, and requires large volumes of toxic organic solvents. A quick, easy, cheap, effective, rugged, and safe method was introduced in 2003 and coupled with selective and sensitive mass detectors to overcome the aforementioned drawbacks. Compared to traditional detectors, mass spectrometers are still far more expensive and not available in most modestly equipped laboratories, owing to maintenance and cost-related issues. Even available, traditional detectors are still being used for analysis of residues in agricultural commodities. It is widely known that the quick, easy, cheap, effective, rugged, and safe method is incompatible with conventional detectors owing to matrix complexity and low sensitivity. Therefore, modifications using column/cartridge-based solid-phase extraction instead of dispersive solid-phase extraction for cleanup have been applied in most cases to compensate and enable the adaptation of the extraction method to conventional detectors. In gas chromatography, the matrix enhancement effect of some analytes has been observed, which lowers the limit of detection and, therefore, enables gas chromatography to be compatible with the quick, easy, cheap, effective, rugged, and safe extraction method. For liquid chromatography with a UV detector, a combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction was found to reduce the matrix interference and increase the sensitivity. A suitable double-layer column/cartridge-based solid-phase extraction might be the perfect solution, instead of a time-consuming combination of column/cartridge-based solid-phase extraction and dispersive solid-phase extraction. Therefore, replacing dispersive solid-phase extraction with column/cartridge-based solid-phase extraction in the cleanup step can make the quick, easy, cheap, effective, rugged, and safe extraction method compatible with traditional detectors for more sensitive, effective, and green analysis. This article is protected by copyright. All rights reserved
... Although few analytical methods have been reported in the literature for determination of JHXJZ in different matrices, we could take advantage of oxadiazon analysis methods as JHXJZ with similar structures (containing 1,3,4-oxadiazole). From then on, oxadiazon residues in different matrices were reported one by one, such as, Odanaka et al. (1991) used solid bonded-phase extraction as alternative to liquid-liquid partitioning for oxadiazon residues in crops, and the recovery was 97 % eluting with 80 % acetonitrile in water. Crane and Younghans-Haug (1992) developed a gas chromatography-mass spectrometry (GC-MS) method to determine oxadiazon residues in sediment, fish, and shellfish. ...
A new method was developed and validated for the determination of 2-(4-fluorophenyl)-5-methylsulfonyl-1,3,4-oxadiazole (jiahuangxianjunzuo, JHXJZ) by ultra-performance liquid chromatography equipped with photo-diode array detector. JHXJZ from tomato and soil was extracted with ethyl acetate without further cleanup. The limits of detection and quantification of JHXJZ were 0.0083 and 0.025 mg kg(-1) in tomato, 0.0017 and 0.005 mg kg(-1) in soil, respectively. The average recoveries of tomato and soil were studied at three spiked levels and ranged from 84.51 % to 101.30 % and 85.30 % to 101.53 %, respectively, with relative standard deviations of 2.61 %-4.13 % and 1.21 %-4.80 %, respectively. The results indicated that the reported method could meet the requirement for the analysis of JHXJZ in trace amount in tomato and soil.
A multi-residue technique is presented for the extraction and quantitative determination of some widely used organochlorine pesticides such as lindane, heptachlor, aldrin, dieldrin, endrin and p,p'-DDT in soil. The chlorinated pesticides were extracted from soil with different solvents, followed by clean-up of the sample extract using C-18 solid phase extraction cartridge; the analytes were eluted with hexane and determined by gas chromatography with electron-capture detection. Average recoveries exceeding 89% were obtained for the pesticides. The solid phase extraction method was applied to extract the lindane from contaminated soil and soil-leachates. Column leaching tests were performed; we found some movement of the lindane between operationally defined soil phases or layers.
Xenobiotics constitute a potential danger to both life and health of humans. The ignorance of properties of xenobiotics used, as well as of the processes they undergo during agrotechnical activities or in plants' inner circulation, may evoke negative effects on the whole ecosystem. Examining the process of sorption of xenobiotics allows us to predict the behavior of pesticides in different systems, to predict the type of processes they undergo, and to determine the main ways of they penetrate plants. The models of pesticides' behavior in plants also allow us to specify management of their microelements. This article points out the basics for determining the process of sorption modeling, describes processes during uptake, and explains the role of phloem and xylem in these processes.
The detailed matrices and their behaviors during pesticide residue analyses were clarified using a metabolomics analysis approach. The matrix profile was investigated using two different extraction solvents, acetone and acetonitrile. Acetone extracted the matrix components with a wide range of log P(O/W) values. Components with log P(O/W) values >10, such as sterols and tocopherols, and components with log P(O/W) values <3.2 were more extracted by acetone than by acetonitrile. In contrast, components with log P(O/W) values in the range from 3.2 to 10 were extracted by both acetone and acetonitrile at the same concentration level. The study also examined the difference in the column cleanup efficiency using a solid phase extraction (SPE). Florisil, silica gel, NH(2), PSA, and GCB were selected as representative columns for pesticide residue analysis, and acetone extraction of brown rice was selected in this experiment. Most of the matrix components were removed by either column, whereas monoacylglycerols, which are the components causing the matrix effect, were not removed by any column. Understanding such a detailed matrix behavior helps to develop a better analytical method for pesticide analysis using GC-MS.
The application of SPE technology to the isolation of pesticides and related compounds from food and soils has grown enormously in the last decade. Much of this growth has been due to the relative ease of sample handling and the wide range of solid supports currently available for a variety of applications. The aim of this review is to present the methods for solid phase extraction (SPE) of pesticide residues from soils and foods. There are three main areas according to the type of approach used to handle the sample: solid phase extraction, solid phase clean-up (SPC), and matrix solid phase dispersion (MSPD). This review covers milk products, fatty foods, fruits, vegetables, and soils. Solid phase materials are discussed in each case in terms of reversed bonded-phase silica sorbents (C18, C8, C2, etc.) and polar sorbents (alumina, Florisil, and silica).
Strategies for multiclass, multiresidue analysis of pesticides depend on several factors that all derive from three fundamental considerations: (1) the need for the results; (2) the form and composition of the matrix; and (3) the time, resources, and technology available to the analyst. First, the need for the data dictates the quality assurance (QA)/quality control (QC) guidelines and the desired analytical figures of merit, such as limits of detection (LOD) and the accuracy and precision of the results. These needs also contribute to the choice of pesticide analytes, which sets the polarity range for the analysis. No single method can determine all pesticides in diverse matrices, so an overall strategy is often used to compartmentalize a series of approaches in order best to detect the targeted pesticides in an effective and efficient process. Second, the various types of matrices that are commonly analyzed for pesticide residues may affect the sample preparation approach employed in the analytical strategy. Common matrices for pesticide analysis consist of solids, liquids, and gases in applications associated with food, agricultural, environmental, and other sample types. Varying degrees of pesticide–matrix interactions in different materials require more or less stringent extraction procedures to separate the pesticides from the sample. Sample preparation in multiclass, multiresidue strategies frequently utilizes liquid–solid, liquid–liquid and other partitioning processes including those, such as pressurized fluid extraction (PFE), in which pressure and temperature of different fluids are controlled. Extracts often require cleanup to remove interfering co-extracted matrix components prior to analysis. A variety of cleanup techniques based on a number of partitioning processes, such as liquid chromatography (LC), may be employed in an on-line or off-line fashion. Lastly, the sample extract is usually further separated and analyzed using one or more techniques. The majority of pesticides are analyzed by gas chromatography (GC) with mass spectrometry (MS) and/or element-selective GC detectors. High-performance liquid chromatography (HPLC) is often used in the analysis of thermally labile pesticides that are not amenable to GC analysis. Other alternatives for analysis of certain pesticide include capillary electrophoresis (CE) and immunoassays. Fundamentally, a high degree of selectivity helps in generating excellent analytical results, but the wide polarity range of analytes in multiclass, multiresidue methods (MRMs) for pesticides necessitates a great deal of effort to attain a high degree of selectivity. Trade-offs and compromises are omnipresent in multiclass, multiresidue analysis of pesticides, and a host of strategies are available depending on how the analytical chemist prioritizes the analytical and practical considerations.
A reversed-phase high performance liquid chromatographic (HPLC) method with an acetonitrile-methanol-water mobile phase gradient and photodiode-array detection (DAD) is described for simultaneous determination of 21 pesticides, frequently used in agriculture, of different types, namely organophosphorus, organochlorine,N-methylcarbamates, triazines and phenylureas in vegetable samples. The pesticides were extracted with acetone and then partitioned from the vegetable sample with dichloromethane. Sample clean-up was accomplished by solid-phase extraction (SPE) using both C18 and florisil SPE columns. Average recoveries from green beans ranged from 70.0 to 110.1%. Detection limits of less than 0.1 mg kg–1 were obtained.
A mixture of twelve intermediate polarity pesticides, mostly carbamate-type, have been chromatographied on an octadecyl-silica
bonded-phase column using acetonitrile-water gradient mobile phase and UV detection. Pesticides were extracted from aqueous
matrix by solid-phase extraction. The extraction system consisted of a glass microcolumn containing octyl-silica solidphase
conditioned with methanol and water. The elution was by acetonitrile-dichloromethane (50:50). Studies of extraction factors
like volume of sample, addition of 10% sodium chloride and presence of dissolved humic material are investigated.
After extraction optimization, it was applied to waters from Lake La Albufera (Valencia, Spain). Some pesticides used in rice
crops were found at concentrations above those allowed by the EEC for natural waters (1–3 µg L−1).
A new LC/MS/MS method of analysis was developed for the common determination of about 100 polar pesticides in foodstuff. Different substances, belonging to the groups of carbamates, urea derivatives, acidics, organophosphates and triazoles, are handled using a unitary procedure of sample preparation. After extraction with methanol and clean up on a solid phase, the pesticides are analysed by LC/MS/MS and two different methods. The calibration was carried out with matrix standards, and the method was validated for different matrices. This quick, cost-effective multi-method is very sensitive and applicable for various vegetable matrices.
A review concerning the determination of pesticide residues in fruit and vegetables is presented. The basic principles and recent developments in the extraction and quantitation of pesticides are discussed. Consideration is given to solid phase and supercritical extraction techniques, automation and robotic systems, and immunoassay procedures.
A fully automated solid-phase extraction gas chromatographic/mass spectrometric (SPE/GC/MS) method was developed for determination of pesticides in wine. All steps from aspiration of infiltrated wine to printout of the integrated chromatogram were performed without human interaction. A dedicated robot performed addition of internal standard, application of wine onto the SPE cartridge, elution of analytes, drying and concentrating of eluate, and passing of concentrate to the GC sampler. All steps were performed in standard liquid chromatography/GC vials, using a minimum of organic solvent. The method permits determination of 21 different pesticides. Individual detection limits were 0.005-0.01 mg/L. The regression coefficients relating to linearity were > 0.99; only 4,4-dichloro-benzphenone and dicofol showed lower coefficients. The recoveries for 17 pesticides ranged from 80 to 115%.
Gel permeation chromatography was applied as a clean-up step in a HPLC multiresidue method for the determination of several pesticides in plants, not amenable to analysis by GC. The pesticides investigated were diflubenzuron, triflumuron, clofentezine, hexythiazox and flufenoxuron. The clean-up technique resulted in a good separation of analytes from co-extractive matrix compounds. Complete HPLC separation of all pesticides was achieved under the conditions selected. The analytical procedure was characterized with high accuracy and precision and acceptable sensitivity to meet requirements for monitoring these pesticides in crops.
A multi-residue method for the simultaneous extraction from drinking water using solid-phase extraction on LiChrolut EN [poly(styrene-divinylbenzene), PSDVB] and determination of nine N-methylcarbamate pesticides (NMCs) (aldicarb, its metabolites i.e. aldicarb sulfone and aldicarb sulfoxide and carbaryl, carbofuran, dioxacarb, ethiofencarb, methomyl and propoxur) using reversed-phase liquid chromatography was studied. A 1000-fold pre-concentration was achieved and the method was used for determination of the nine pesticides in water, with limits of detection in the range 3-15 ng L(-1). For all compounds the recoveries determined at the 0.1 and 1 microg L(-1) level generally ranged from 85 to 104% with relative standard deviations (RSD) of 1.4-8.8%.
A sensitive gas chromatographic method using an electron-capture detector (ECD) has been developed for the determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans. The developed method consists of extraction with methanol, partition with methylene chloride, and column chromatographic clean-up, followed by capillary gas chromatographic determination. The recoveries of both fungicides were greater than 90% for both plant samples. The limits of determination of the method were 0.001 ppm for both fungicides. The method was applied to determine residues and the rate of disappearance of tetraconazole and diniconazole from tomatoes and green beans [open field treatment, 50 cc of Domark 10% EC (emulsifiable concentrate), and 35 cc of Sumi-eight 5% EC; both for 100 l of water]. The fungicides incorporated into the plants decreased rapidly with a half-life around 3 days for diniconazole and from 4.5 to 6.5 days for tetraconazole. No residues could be detected in the plants during the period of study of 21 days after field application. Hence, the plants could be used safely after that period of time.
A cartridge sampling technique for priority pollutants in wastewater has been developed using bonded phase silica adsorbents.
This technique has been compared to the EPA Method 625 which requires liquid-liquid extraction of the wastewater. The disposable
bonded reversed-phase cartridges were evaluated for all the phenols and 22 neutral pollutants. These compounds were chosen
purposely to cover a wide range of solubility and polarity characteristics. The cartridge extractions of spiked water samples
yielded recoveries between 50 and 110%, which were better or equal to recoveries on the same samples using Method 625 liquid
extraction. The relative standard deviation of overall recoveries for all pollutants was less than 15%. The detection limits
achieved were approximately 50 and 10 ppb (in water) for the phenols and neutrals, respectively.
A systematic study that compares the recoveries of selected organophosphorus pesticides from spiked deionized water using
octyl and octadecyl bonded silica sorbents (solid phase extraction, SPE) is reported. A packed column GC is converted to accept
a dual wide-bore capillary configuration with chemically dissimilar liquid phases. One column leads to a thermionic detector
while the other column leads to a flame photometric detector. The experimental design affords replicate injections and replicate
extraction recovery data. Relative standard deviations are calculated that take into account propagation of error for i replicate injections on each of g SPEs performed. The polarity of the dialkyl phosphate ester moiety is correlated with the SPE extraction efficiency.
Solid-phase extraction is an emerging chromatographic sample preparation technology. It is an improved alternative to traditional methods of extracting and concentrating organic compounds from aqueous solutions. Successful application of solid-phase extraction to aqueous environmental samples is illustrated for the trace enrichment of herbicide residues. Because retention and elution are confounded during solid-phase extraction method development, it is difficult to optimize one before the other. A plan for developing single-residue analytical protocols is discussed, and the influence of pH, sample concentration and volume, sorbent mass, and solvent strength and volume on the removal of trace organics from water is illustrated.
Summary A method for the direct determination of seven carbamate insecticides (bendiocarb, carbofuran, carbaryl, dioxacarb, ethiofencarb, pirimicarb, and propoxur) on fruits and vegetables by capillary gas chromatography and AFID was worked out. The sample is extracted with ethyl acetate, taken up in water and passed through a C18 Sep-pak cartridge. The recoveries at 0.5 ppm lie between 65 and 110% and the detection limits are between 5 and 50 ppb. Among 50 analysed samples 2 had traces of carbamates. Residues of pirimicarb on treated lettuce and apples were less than 0.2 ppm 7 days after application and residues of ethiofencarb on treated lettuce were less than 0.03 ppm. In methodical preinvestigations the behaviour of the seven carbamates and also of aldicarb and methomyl when using different injector conditions is described.
A procedure for isolation of hazardous organic compounds from water for gas chromatography/mass spectrometry analysis is presented and applied to creosote- and pentachlorophenol-contaminated groundwater resulting from wood-treatment processes. This simple procedure involved passing a 50-100 mL sample through a bonded-phase extraction column, eluting the trapped organic compounds from the column with 2-4 mL of solvent, and evaporating the sample to 100 micro-L with a stream of dry nitrogen, after which the sample was ready for gas chromatography/mass spectrometry analysis. Representative compounds indicative of creosote contamination were used for recovery and precision studies from the cyclohexyl-bonded phase. Recovery of these compounds from n-octyl-, n-octadecyl-, cyclohexyl-, and phenyl-bonded phases was compared. The bonded phase that exhibited the best recovery and least bias toward acidic or basic compounds was the n-octadecyl phase. Detailed compound identification is given for compounds isolated from creosote- and pentrachlorophenol-contaminated groundwater using the cyclohexyl-bonded phase. 12 references, 1 figure, 4 tables.
Mode operatoire d'une methode de chromatographie gazeuse et de CLHP pour le dosage des residus d'herbicide dans des echantillons de pommes, de raisins, de tomates, de poires, de fraises, d'oranges et de pommes de terre