This paper reports the bioefficacy of selected insecticides against thrips and their pre-harvest intervals (PHI) in onion pertaining to their recommended application rates and maximum residue limits. Profenophos, methomyl and imidacloprid showed comparatively higher bioefficacy against thrips. GC-MS and LC-MS/MS-based residue analysis methods in onion bulbs and composite matrix of ...

Five pesticide formulations registered for use in Canada containing organophosphate-insecticide active ingredients azinphos-methyl, chlorpyrifos, diazinon, malathion and phorate were subjected to treatment by membrane bioreactor (MBR) technology. The target active ingredients were introduced to the MBR at ppm level concentrations. The biodegradation of these compounds was analyzed daily using selected ...

We have developed a method for the determination of melamine (MEL), ammeline (AMN), and ammelide (AMD) by surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs). The major peaks for MEL, AMN, and AMD at m/z 127.07, 128.05, and 129.04 are assigned to the [MEL + H](+) , ...

Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is frequently used for analysis of cannabinoids in drug abuse control. Despite differences in structure, the isomers Δ(9) -tetrahydrocannabinol (THC) and cannabidiol (CBD) provide identical fragment spectra after positive electrospray ionization (ESI). For elucidation of the reason, hydrogen/deuterium (H/D) exchange experiments were performed. Solutions of ...

Busulfan (Bu) is an important component of the myeloablative conditioning regimen prior to hematopoietic stem cell transplantation (HSCT) especially in children. Intravenously administered Bu exhibits a therapeutic window phenomenon requiring therapeutic drug monitoring. Analytical methods developed for Bu routine monitoring were aimed at using low volumes of biological fluids and ...

The linear range of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) bioanalytical assay is typically about three orders of magnitude. A broader standard curve range is favored since it can significantly reduce the time, labor and potential errors related to sample dilution - one of the bottlenecks in sample analysis. Using ...

Cyanobacteria are a small group of photosynthetic planktonic bacteria, producing a large group of strong hepatotoxins called microcystins (MCs). Many studies have been conducted to evaluate the presence of MCs and nodularin (NOD) in water or in marine organisms, but little research has been done on the atmospheric environment. Waterborne ...

Carbohydrates are good source of drugs and play important roles in metabolism processes and cellular interactions in organisms. Distinguishing monosaccharide isomers in saccharide derivates is an important and elementary work in investigating saccharides. It is important to develop a fast, simple and direct method for this purpose, which is described ...

Withania somnifera is a rich source of biologically active secondary metabolites. Our earlier investigations on the fruits of this plant have yielded novel compounds, withanamides, with potent antioxidant activity and protective effect on β-amyloid-induced cytotoxicity in vitro. However, several minor compounds present in the fruits have not been characterized previously ...

Esterase inhibitors are widely used to stabilize ester-containing drugs in biological matrices for quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) assays. These co-existing inhibitors could cause matrix effects on bioanalysis and jeopardize the assay performance. We therefore developed an LC/MS/MS methodology to monitor the fate of inhibitors and evaluate their matrix ...

Differentiation of underivatized monosaccharides is essential in the structural elucidation of oligosaccharides which are closely involved in many life processes. So far, such differentiation has been usually achieved by electrospray ionization mass spectrometry (ESI-MS). As an alternative to ESI-MS, atmospheric pressure chemical ionization mass spectrometry (APCI-MS) should provide complementary results. ...

Bergenia crassifolia is a plant widely used in herbal medicine. Its chemical composition has been little studied, and no studies using high-resolution mass spectrometry (HRMS) have been performed. Its phenolic components are of particular interest, due to the interest in such compounds in medicine and cosmetics. The ID-CUBE, a simplified ...

The properties of carbohydrates are determined in part by the number and stereochemical arrangement of their hydroxyl groups. To facilitate their analysis, rapid methods are needed to identify and enumerate hydroxyl groups in sugars and polyalcohols, especially methods that are water-based. The present report details the results of an alternative ...

The Direct Analysis in Real Time (DART) ionization source coupled with a quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples from complex Chinese herbal preparations without sample cleanup or chromatographic separation. In this work, a method based on DART/Q-TOF MS/MS has ...

In the continued search for melanogenesis inhibitors from microbial metabolites, we found that the culture broth of Clitocybe sp. MKACC 53267 inhibited melanogenesis in B16F10 melanoma cells. The active component was purified by solvent extraction, silica gel chromatography, Sephadex LH-20 column chromatography, and finally by preparative HPLC. Its structure was ...

Xylazine, a veterinary sedative, has been found as an adulterant of heroin in street drugs in Puerto Rico. It was found in combination with free morphine and 6-acetylmorphine, codeine, cocaine and benzoylecgonine in postmortem cases at the Puerto Rico Institute of Forensic Sciences (PRIFS). Xylazine is not approved for human ...

Five acylation reagents have been compared for use as derivatizing agents for the analysis of amphetamine-type stimulants (ATS) in urine by gas chromatography-mass spectrometry (GC-MS). The evaluated reagents were heptafluorobutyric anhydride, pentafluoropropionic anhydride, trifluoroacetic anhydride, acetic anhydride (AA) and N-methyl-bis(trifluoroacetamide). The ATS included amphetamine, methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) ...

A method has been developed for the quantitation of isotopic labeling of proteins using liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the application of protein nuclear magnetic resonance (NMR) studies. NMR relies on specific isotopic nuclei, such as (13) C and (15) N, for detection and, therefore, isotopic labeling is an ...

A two-layered polymeric membrane is employed for the formation of separated dried plasma spots from whole blood as an alternative to the direct analysis of whole dried blood spots (DBS). This dried plasma spot (DPS) analysis procedure precludes potential issues of hematocrit differences in whole blood samples while providing pharmokinetic ...

Mass spectrometry (MS) is increasingly employed for the discovery of clinical biomarkers. However, due to sensitivity limitations related to in-source ionization yield, many potential biomarkers are not detected by standard mass spectrometers. Therefore, more efficient ion-source technologies are needed to improve MS applications in biomarker discovery. Among novel ion-source technologies, ...

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight-time-of-flight (TOF-TOF) post-source decay (PSD) tandem mass spectrometry (MS/MS) has seen increasing use for analysis of non-digested protein ions for top-down proteomic identification. However, there is no commonly accepted calibrant for this purpose beyond the use of peptide calibrants whose fragment ions span a lower mass-to-charge ...

Isoprostanes (IsoPs) are a series of prostaglandin (PG)-like compounds formed non-enzymatically through free-radical-induced peroxidation of arachidonic acid. They are considered as 'gold-standard' biomarkers for oxidative stress, in general, and lipid peroxidation, in particular. A new qualitative and quantitative analytical method for the determination of 13 eicosanoids in human urine using ...

The Amazonian region from Brazil has a wide variety of native and wild non-commercially cultivated fruits. This paper reports for the first time the composition of carotenoids and phenolic compounds from Caryocar villosum fruit pulp, and in addition, its proximate composition and antioxidant capacity (ORAC assay) were determined. According to ...

An immunoaffinity chromatographic (IAC) method for the selective extraction and concentration of 13 organophosphorus pesticides (OPs, including coumaphos, parathion, phoxim, quinalphos, dichlofenthion, triazophos, azinphos-ethyl, phosalone, isochlorthion, parathion-methyl, cyanophos, disulfoton and phorate) prior to analysis by HPLC-MS/MS was developed. The IAC column was prepared by covalently immobilizing a monoclonal antibody with ...

A drift tube capable of simultaneously functioning as an ion funnel is demonstrated in proton transfer reaction mass spectrometry (PTR-MS) for the first time. The ion funnel enables a much higher proportion of ions to exit the drift tube and enter the mass spectrometer than would otherwise be the case. ...

Multi-stage mass spectrometry (MS(n)) generating so-called spectral trees has proven itself as a powerful approach in the annotation and structural elucidation of metabolites and is increasingly used in the area of accurate mass LC/MS-based metabolomics. As a consequence, there is a growing need for computational tools specifically designed for the ...

Significant developments in the field of ambient desorption/ionization mass spectrometry (MS) have led to high-throughput direct analysis and imaging capabilities. However, advances in coupling ambient ionization techniques with standalone drift tube ion mobility spectrometry (DTIMS) have been comparatively slower, despite the attractive ruggedness and simplicity of IMS. In this study, ...

Comprehensive two dimensional gas chromatography (GC × GC) provides greater separation space than conventional GC. Because of fast peak elution, a time of flight mass spectrometer (TOFMS) is the usual structure-specific detector of choice. The quantitative capabilities of a novel GC × GC fast quadrupole MS were investigated with electron ...

A suction-free interfacing method was developed for microchip electrophoresis hyphenated with inductively coupled plasma mass spectrometry (MCE-ICP-MS). The hyphenated system was composed of a microchip, a demountable capillary microflow nebulizer (d-CMN) combined with a heated single pass spray chamber, a negative pressure sampling device, a high voltage power supply, a ...

7,8-Dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dGuo) is a useful biomarker of oxidative stress. However, its analysis can be challenging because 8-oxo-dGuo must be quantified in the presence of dGuo, without artifactual conversion to 8-oxo-dGuo. Urine is the ideal biological fluid for population studies, since it can be obtained non-invasively and it is less likely ...

Glucuronidation does not only play a detoxyfying role in living body, but also can complicate pharmacological and toxicological profiles of new drug candidates by forming active and reactive conjugated metabolites. The opportunities of structure elucidation of conjugated metabolites have therefore been increased in drug metabolism studies at early development stage. ...

The application of zebrafish (Danio rerio) larvae to drug discovery assays and toxicity testing, and the occurrence of pharmaceuticals in the environment, has resulted in a need to understand the extent of the metabolic capabilities in the early life stages of this species. The aims of this study were to ...

Capillary electrophoresis-mass spectrometry (CE-MS) has emerged as a powerful technique for the analysis of proteins and peptides. Over the past few years, significant progress has been made in the development of novel and more effective interfaces for hyphenating CE to MS. This review provides an overview of these new interfacing ...

Rapid and cost-effective MALDI-TOF MS-based systems will replace conventional phenotypic methods for routine identification of bacteria. We report here the first evaluation of the new MALDI-TOF MS-based VITEK MS system in a large clinical microbiology laboratory. This system used an original spectra classifier algorithm and a specific database designed for ...

Synthetic cannabinoids sprayed on herbal mixtures have been abused as a new designer drug all over the world since 2004. In 2008, the first compounds, CP 47,497 and JWH-018, were identified as active ingredients in these mixtures. Most of the compounds have been synthesized for research purposes and are potent ...

In recent years, derivatives of cathinone, a naturally occurring beta-keto phenylethylamine, have entered the illicit drug market. These compounds have been marketed over the internet or in so-called head shops as "legal highs" and have gained popularity among drug users. Numerous fatalities due to the abuse of these drugs in ...

  New Zealand is a leader in the global dairy industry. Milk powder is the principal export product, but there is also a prominent cheese manufacturing industry, catering more for the domestic market. The Selected Ion Flow Tube-Mass Spectrometric (SIFT-MS) technique was used to compare 4 New Zealand cheeses marketed ...

Bacillus subtilis XF-1 (CGMCC No. 2357), a patent strain with good effects for controlling the clubroot of crucifer and many pathogenic fungi, was predicted to produce cyclic lipopeptide (CLP) antibiotics based on its genomic analysis. In this study, the CLPs were purified and determined with the following protocol: the supernatant ...

A fast and reliable online identification of pollen is not yet available. The identification of pollen is based mainly on the evaluation of morphological data obtained by microscopic methods. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) was applied to the analysis of extracts and milled pollen samples. The obtained MALDI ...

Crude oil samples are very complex mixtures of compounds and only Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides the ultra-high mass resolution necessary to resolve them. However, FT-ICR MS operates best when only a small amount of ions is present during each transient. This cannot be accomplished ...

Oxazolines have attracted the attention of researchers worldwide due to their versatility as carboxylic acid protecting groups, chiral auxiliaries, and ligands for asymmetric catalysis. Electrospray ionization tandem mass spectrometric (ESI-MS/MS) analysis of five 2-oxazoline derivatives has been conducted, in order to understand the influence of the side chain on the ...

A study of pesticide transformation products (TPs) was carried out in soils of agricultural areas working under integrated pest management programs (IPMs). Bupirimate and cyromazine were the pesticides detected in soils after an initial pre-screening. The aim of this work was the identification of relevant TPs of these two pesticides. ...

Dozens of synthetic cannabinoid analogs purposefully meant to circumvent legal restrictions associated with controlled substances continue to be manufactured and promoted as producing 'legal highs'. These designer drugs are difficult to identify in conventional drug screens not only because routine protocols have not been developed for their detection, but also ...

Traditionally, anthocyanin analysis in mass spectrometry is carried out in the positive ionization mode only. A study of the mass spectrometric behaviors of anthocyanins in the negative ionization mode revealed interesting characteristics that was not previously reported. It can be used to differentiate anthocyanins from other non-anthocyanin polyphenols. An ultra-high-performance ...

Sphingolipids are important components of cell membranes that serve as cell signaling molecules; ceramide plays a central role in sphingolipid metabolism. De novo ceramide biosynthesis depends on fatty acid availability, but whether muscle uses circulating free fatty acids or pre-existing intracellular stores is unknown. Our goal was to develop a ...

The LA-MC-ICP-MS method applied to U-Pb in situ dating is still rapidly evolving due to improvements in both lasers and ICP-MS. To test the validity and reproducibility of the method, 5 different zircon samples, including the standard Temora-2, ranging in age between 2.2 Ga and 246 Ma, were dated using ...

Mass spectrometry coupled to high-performance liquid chromatography (HPLC-MS) is evolving more quickly than ever. A wide range of different instrument types and experimental setups are commonly used. Modern instruments acquire huge amounts of data, thus requiring tools for an efficient and automated data analysis. Most existing software for analyzing HPLC-MS ...

We present three fatal intoxications of methylone, a cathinone derivative. Blood was analyzed with a routine alkaline liquid-liquid extraction and analyzed by gas chromatography coupled with a mass spectrometer (GC-MS). Methylone was identified by a full scan mass spectral comparison to an analytical standard of methylone. For a definitive and ...

A novel multiresidue analysis method is developed for the determination of twenty phthalate esters at μg/kg level in edible vegetable oils by microwave-assisted extraction-gel permeation chromatography-solid phase extraction-high resolution gas chromatography-tandem mass spectrometry (MAE-GPC-SPE-HRGC-MS/MS). The samples were extracted with methanol under microwave incubation. Clean-up was carried out with GPC followed ...

In this study, we conducted polychlorinated biphenyls (PCBs) analysis using fast gas chromatography (GC)/high-resolution mass spectrometry (HRMS). Mass spectrometry (MS) was performed with a miniature multi-turn time-of-flight (TOF) analyzer called "MULTUM-S II". MULTUM-S II is truly a portable high resolution mass spectrometer. The mass spectrometer's high resolution capability is due ...