John Castro

• Ph.D in Applied Chemistry
• Professor at Universidad Del Sinu - Seccional Cartagena

A new hyphenated technique using thin-layer chromatography (TLC) to separate analytes in mixtures, coupled with mid-infrared (MIR) laser spectroscopy for identification and quantification, is presented. The method, which provides a means for rapid screening of analytes that is practical, low-cost, fast, robust, and reproducible, was tested using ni...

A hybrid material composed of IRMOF-3 and ZnO (IRMOF-3/ZnO) was synthesized to enhance photocatalytic methylene blue (MB) degradation under visible-light irradiation. Scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and diffuse-reflectance UV-Vis analyses confirmed the successful integration of ZnO into the...

The development of new methods of identification of active pharmaceutical ingredients (API) is a subject of paramount importance for research centers, the pharmaceutical industry, and law enforcement agencies. Here, a system for identifying and classifying pharmaceutical tablets containing acetaminophen (AAP) by brand has been developed. In total,...

In this study, the impact of ethylene oxide, propylene oxide, 1,2-butene oxide, and 1,2-pentene oxide on the polymerization of propylene at an industrial level was investigated, focusing on their influence on the catalytic efficiency and the properties of polypropylene (PP) without additives. The results show that concentrations between 0 and 1.24...

Mid‐infrared laser spectroscopy was used to investigate common bacteria encountered in biopharmaceutical industries. The study involved the detection of bacteria using quantum cascade laser spectroscopy coupled to a grazing angle probe (QCL‐GAP). Substrates similar to surfaces commonly used in biopharmaceutical industries were used as support media...

We report on the spectroscopic investigation of common bacteria encountered in biopharmaceutical industries with spectroscopic definition and specificity using mid-infrared laser spectroscopy. This study describes the detection of three different bacteria species using quantum cascade laser spectroscopy coupled to a grazing angle probe (QCL-GAP). S...

Pages: 406-424 Resumen: La detección de materiales altamente energéticos (HEM), también llamados explosivos, es un tema de interés en todo el mundo. Cada año se pierden muchas vidas y bienes debido al uso inadecuado de estas sustancias. Esta investigación utiliza una metodología analítica basada en la espectroscopia vibracional tales como infrarroj...

The detection of highly energetic materials (HEMs), also called explosives, is a topic of interest worldwide. Many lives and property are lost every year due to the inappropriate use of these substances. In this research, an analytical methodology based on infrared (IR) vibrational spectroscopy is used to detect explosives. Transmittance mode spect...

One route of exposure to SPAs is through bottled water since the polymers used to make plastic bottles contain these SPAs, which migrate from the plastic to the water. Solid-phase extraction (SPE), HPLC-MS, FTIR, and DSC are used to identify and quantify these SPAs in water. Interday measurements of cyanox 1790 in water with HPLC showed RSD, error,...

The copolymer synthesis process can be affected by failures in the production process or by contaminating compounds such as ketones, thiols, and gases, among others. These impurities act as an inhibiting agent of the Ziegler–Natta (ZN) catalyst affecting its productivity and disturbing the polymerization reaction. In this work, the effect of formal...

Microplastic (MP) contamination has become a problem of great interest to the community at large. The detection of these particles in different ecosystems and foods has been the subject of study. However, the focus of these investigations has been on the identification and quantification of PM by DSC and Pyr-GC/MS and not on how they are transporte...

In the present work, four (4) samples of sylvite (KCl) from different deposits in Canada, Belarus and Germany were analyzed in order to determine the differences between them in terms of chemical composition, morphology and impurities present. Different non-instrumental and instrumental techniques were used. A scanning electron microscope analysis...

For the synthesis of polymeric resins, it is of great importance to review the raw materials and the equipment to be used to avoid the presence of compounds that may affect the effectiveness of the polymerization and the characteristics of the plastic to be obtained. Iron oxide is a compound that can be present in reactors after maintenance due to...

It is my great pleasure to introduce the fifth volume from our popular open access Book Series ‘Advances in Optics: Reviews’ started by the IFSA Publishing in 2018. The Vol. 5 of this Book Series is also published as an Open Access Book in order to significantly increase the reach and impact of this volume, which also published in two formats: elec...

The process analytical technology (PAT) initiative proposed by the US Food and Drug Administration (FDA) suggests innovative methods to better understand pharmaceutical processes. The development of analytical methods that quantify active pharmaceutical ingredients (APIs) in powders and tablets is fundamental to monitoring and controlling a drug pr...

The synthesis of molecules such as humic acids is a good strategy for the remediation of eroded soils. Since the synthesis and extraction of these carbon molecules do not represent a process of energy liberation of the carbon, it is also a low-cost process. Bad practices in soils, such as the indiscriminate use of pesticides and pesticides, cause d...

In the following work, the practical implementation of a radial distribution system will be carried out. This work is done in the GAMS software. In the present work the analysis will be carried out to three radial systems of 10, 33, 69 nodes. In which it is expected to analyze the best location of distributed generation systems (GD) and batteries (...

Mineral grade and commercial grade bentonite pillared clays were prepared with SnO 2 . This is to create adsorbents for removal of contaminants from water. The initial and modified clays were characterized by X-ray fluorescence (XRF), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and nitrogen sortometry. The results of the chemi...

The acquisition or development of a software in a company must always obey to meet a specific need, either to carry out a process in a better way or as an added value to a process that is currently managed efficiently. Such is the case of the web system for the management of requests, complaints, claims and suggestions (PQRS) of the Antonio de Arév...

Abstract. The spatial distribution of metals in the water for consumption in the different supply sources, natural sources, family storage tanks and deep wells were studied. 16 samples were made for different municipalities belonging to the department of La Guajira upper part. The water samples were analyzed in 2016 and analyzed physically and chem...

A full time-direct Boundary Element Formulation for the dynamic analysis of elastic membranes coupled to acoustics fluid is presented. The elastic membranes is modeled using the classical linear elastic pre-stretched membrane theory. The acoustic fluid is modeled using the acoustic-wave equation for homogeneous, isotropic, inviscid and irrotational...

A novel full Boundary Element Formulation for the harmonic analysis of elastic membranes coupled to acoustics fluid is presented. The elastic membranes is modeled using the classical linear elastic pre-stretched membrane theory. The acoustic fluid is modeled using the acoustic-wave equation for homogeneous, isotropic, inviscid and irrotational flui...

The spatial distribution of metals in the water for consumption in the different supply sources, natural sources, family storage tanks and deep wells were studied. 16 samples were made for different municipalities belonging to the department of La Guajira upper part. The water samples were analyzed in 2016 and analyzed physically and chemically and...

Acetaminophen (AAP) is an active ingredient very used in many pharmaceutical preparations. AAP is a pain reliever and a fever reducer drug. Generally, it is used to treat many conditions such as headache, muscle aches, arthritis, backache, toothaches, colds, and fevers. Standard methods most used for AAP chemical detection are based on chromatograp...

Owing to scientific advances in the field of materials sciences and engineering, researchers have developed new energy sources used for spectroscopic applications and measurements of properties resulting from the interaction of matter and electromagnetic radiation in the mid-infrared (MIR) region. MIR lasers, such as quantum cascade lasers (QCLs),...

The contamination of bodies of water by heavy metals represents not only a danger for the environment, but also for human health; because they do not have the capacity to biodegrade, accumulate in the environment and in the tissues of the living organisms that inhabit it. In order to minimize these impacts, Zinc adsorption (Zn) was studied in aqueo...

Este trabajo trata sobre la comparación de la asignación teórica del espectro vibracional de DADP con los desplazamientos experimentales por marcación isotópica. Para ello, se sintetizaron los isotopómeros DADP-C4 y DADP-C2, los cuales son isotopómeros parcialmente marcados. DADP-C4 y DADP-C2 fueron sintetizados a partir de acetona marcada isotópic...

Two standoff detection systems were assembled using an infrared telescope coupled to a Fourier transform infrared spectrometer, a cryocooled mercury-cadmium telluride detector, and a telescope-coupled midinfrared excitation source. Samples of the highly energetic materials (HEMs) 2,4,6-trinitrotoluene (TNT) and pentaerythritol tetranitrate (PETN) w...

A quantum cascade laser spectrometer was used to obtain the reflection spectra of highly energetic materials (HEMs) deposited on nonideal, low-reflectivity substrates, such as travel-bag fabric (polyester), cardboard, and wood. Various deposition methods were used to prepare the standards and samples in the study. The HEMs used were the nitroaromat...

A non-linear thermal fitting, which was theoretically supported, was used to determine sublimation enthalpies of cyclic organic peroxide explosives using thermogravimetry analysis and FT-IR grazing-angle techniques. TG and FT-IR grazing-angle experiments consisted in the determination of mass loss rate at several isothermal points. The sublimation...

Vibrational standoff detection of explosives has been addressed using Raman, FT-IR and quantum cascade laser spectroscopies. Effects of parameters such as angle of incidence, distance, surface concentrations and substrates were investigated.

A standoff multivariate calibration for detection of highly energetic materials (HEM) using Fourier transform infrared spectroscopy is presented in this report. The procedure consists in standoff sensing at 1 m distance and the variation of three parameters of detection. The first variable considered was the angular dependence: 0° to 45° from sourc...

Active mode standoff measurement using infrared spectroscopy were carried out in which the angle between target and the source was varied from 0-70° with respect to the surface normal of substrates containing traces of highly energetic materials (explosives). The experiments were made using three infrared sources: a modulated source (Mod-FTIR), an...

An infrared spectroscopy based explosives detection system using a quantum cascade laser (QCL) as excitation source was used to record mid infrared spectral signals of highly energetic materials (HEM) deposited on real world substrates such as travel baggage, cardboard and wood. The HEMs used were nitroaromatic military explosive trinitrotoluene (T...

Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area...

Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area...

A standoff multivariate calibration for detection of highly energetic materials (HEM) using Fourier transform infrared spectroscopy is presented in this report. The procedure consists in standoff sensing at 1 m distance and the variation of three parameters of detection. The first variable considered was the angular dependence: 0° to 45‡ from sourc...

A methodology for processing spectroscopic information using a chemometrics-based analysis was designed and implemented in the detection of highly energetic materials (HEMs) in the gas phase at trace levels. The presence of the nitroaromatic HEM 2,4-dinitrotoluene (2,4-DNT) and the cyclic organic peroxide triacetone triperoxide (TATP) in air was de...

A standoff detection system was assembled by coupling a reflecting telescope to a Fourier transform infrared spectrometer equipped with a cryo-cooled mercury cadmium telluride detector and used for detection of solid-phase samples deposited on substrates. Samples of highly energetic materials were deposited on aluminum substrates and detected at se...

The detection of harmful materials in bulk and trace levels present in different matrices: gases/vapors, liquids, and solids is an important consideration for the development of sensors and standoff detection systems for use in National Defense and Security applications. Hazardous chemicals such as highly energetic materials (HEM), homemade explosi...

A methodology for processing spectroscopic information using a chemometrics-based analysis was designed and implemented in the detection of highly energetic materials (HEMs) in the gas phase at trace levels. The presence of the nitroaromatic HEM 2,4-dinitrotoluene (2,4-DNT) and the cyclic organic peroxide triacetone triperoxide (TATP) in air was de...

Spectroscopy based standoff detection systems: Raman and FTIR have been tested for detection of threat chemicals, including highly energetic materials, homemade explosives, explosives formulations and high explosives mixtures. Other threat chemicals studied included toxic industrial compounds (TIC) and chemical agent simulants. Microorganisms and b...

The remote detection of highly energetic materials (HEM) based on vibrational spectroscopy is an important topic to include in the review of the classification, composition and properties of explosives. Infrared and Raman spectroscopies allow for the detection and remote identification of chemicals and biological threats and also enable the use of...

A review of recent developments in MIR spectroscopy that have potential for field deployment in defense and homeland security applications for standoff detection of highly energetic materials (HEM) and homemade explosives (HME), as well as in forensic sciences applications

A remote infrared spectroscopy (RIRS) detection system was assembled using a mid infrared (MIR) Fourier Transform interferometer useful in open-path (OP) mode, a reflective infrared telescope and a cryocooled wide band, MCT detector. The system was used for passive mode IR thermal emission measurements and was also coupled to another Newtonian tele...