Occurrence of organotin compounds in food: increasing challenge of phenyltin compounds.

Concentrations and distribution for 16 organotin compounds were studied in all kinds of foods, including seafood, agricultural products, and wine. Meanwhile, the degradation of the TBT or TPhT was also evaluated. Concentrations of total organotins in seafood, agricultural products, and wine were 1047.

Simultaneous determination of cyanide and thiocyanate in milk by GC-MS/MS using cetyltrimethylammonium bromide as both phase transfer catalyst and protein precipitant.

A method was developed for simultaneous determination of cyanide and thiocyanate in milk by gas chromatography-tandem quadrupole mass spectrometry (GC-MS/MS). Cyanide and thiocyanate were derivatized with pentafluorobenzyl bromide (PFBBr) as PFB-CN and PFB-SCN, respectively. Cetyltrimethylammonium bromide (CTAB) was employed both as a phase transfer catalyst and a protein precipitant in the sample pretreatment, which facilitates the separation of the organic and aqueous phases, and greatly simplifies the pretreatment procedures to achieve simultaneous and rapid determination of cyanide and thiocyanate.

Comprehensive investigation of the content and the origin of matrine-type alkaloids in Chinese honeys.

A HPLC-MS/MS method for simultaneous determination of four matrine-type alkaloids (matrine, oxymatrine, sophocarpine and sophoridine) in honey was established and was applied to 567 Chinese honey samples. The overall detection rate was 61.0 % and all eight Sophora viciifolia Hance honey samples were detected with the average content of 1183.

Simultaneous determination of seven perfluoroalkyl carboxylic acids in water samples by 2,3,4,5,6-pentafluorobenzyl bromide derivatization and gas chromatography-mass spectrometry.

A new derivatization reagent, 2,3,4,5,6-pentafluorobenzyl bromide (PFBBr), was employed to determine seven perfluoroalkyl carboxylic acids (PFCAs) simultaneously in tap water with gas chromatography-mass spectrometry (GC-MS) technique in this study. Firstly, seven PFCAs were derivatized to their corresponding esters under alkaline condition. The derivatization conditions including the amount of PFBBr and KCO, derivatization temperature and time were optimized to increase the derivatization efficiency.

A comprehensive analysis of C isotope ratios data of authentic honey types produced in China using the EA-IRMS and LC-IRMS.

In the current study, we have comprehensively analyzed different kinds of pure honey which was produced in various areas in China according to δC-EA -IRMS (AOAC method 998.12) and δC-LC-IRMS (proposed by the Intertek laboratory in Europe) methods. As for the δC-EA -IRMS method, the study was confirmed that the C4 sugar of all authentic honey samples was qualified.

Wide-scope screening of pesticides in fruits and vegetables using information-dependent acquisition employing UHPLC-QTOF-MS and automated MS/MS library searching.

This paper presents an application of ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) for simultaneous screening and identification of 427 pesticides in fresh fruit and vegetable samples. Both full MS scan mode for quantification, and an artificial-intelligence-based product ion scan mode information-dependent acquisition (IDA) providing automatic MS to MS/MS switching of product ion spectra for identification, were conducted by one injection. A home-in collision-induced-dissociation all product ions accurate mass spectra library containing more than 1700 spectra was developed prior to actual application.

High Throughput Analytical Techniques for the Determination and Confirmation of Residues of 653 Multiclass Pesticides and Chemical Pollutants in Tea by GC/MS, GC/MS/MS, and LC/MS/MS: Collaborative Study, First Action 2014.09.

Thirty laboratories from fom North and South America, Europe, and Asia participated in this AOAC collaborative study (15 from China; five from Germany; two each from Italy and the United States; and one each from the Republic of Korea, Canada, Spain, Japan, Belgium, and India). Participants represented government regulatory, commercial testing, university, research institute, and private laboratories. The single-laboratory validated (SLV) tea method was evaluated in the collaborative study to determine the recovery and reproducibility of the method under multilaboratory conditions.

Multi-class, multi-residue analysis of trace veterinary drugs in milk by rapid screening and quantification using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

A simple and rapid multi-class multi-residue analytical method was developed for the screening and quantification of veterinary drugs in milk by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). A total of 90 veterinary drugs investigated belonged to almost 20 classes including lincomycins, macrolides, sulfonamides, quinolones, tetracyclines, β-agonists, β-lactams, sedatives, β-receptor antagonists, sex hormones, glucocorticoids, nitroimidazoles, benzimidazoles, nitrofurans, and some others. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure was developed for the sample preparation without the solid-phase extraction step.

Comprehensive determination of polycyclic aromatic hydrocarbons in Chinese herbal medicines by solid phase extraction and gas chromatography coupled to tandem mass spectrometry.

A simple and highly sensitive gas chromatography-tandem mass spectrometry (GC-MS/MS) method combined with solid-phase extraction cleanup was established for the comprehensive determination of 16 Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in various kinds of Chinese herbal medicines (CHMs). A solid-phase extraction (SPE) purification strategy, including three parallel procedures, was developed depending on sample type, and satisfactory purification performances were achieved for all selected CHMs. The limits of detection ranged from 0.

[Simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide residues in fruits and vegetables by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry].

A method for the simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide residues in fruits and vegetables was developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The samples were firstly digested by HC1/THF (1 :10, v/v), then extracted by hexane and followed by the derivatization with Grignard reagent (EtMgBr). Then after purification using florisil SPE columns, the sample extracts were finally analyzed by GC-MS/MS.

[Simultaneous determination of delta13C values of glycerol and ethanol in wine by liquid chromatography coupled with isotope ratio mass spectrometry].

A novel procedure was established for the characterization of delta13C values of glycerol and ethanol in wine by liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). Several parameters influencing the separation of glycerol and ethanol from wine matrix were optimized. The precision and accuracy of the proposed method were 0.

[Simultaneous determination of 57 residual volatile organic solvents in honey by headspace gas chromatography-mass spectrometry].

A method was developed for the simultaneous determination of 57 residual volatile organic solvents (including several alkanes, aromatic hydrocarbons, alcohols, ketones, esters and ethers) in honey by headspace gas chromatography-mass spectrometry (HS-GC/MS). The honey sample was dissolved with water in a headspace vial, and the equilibration of the sample in the headspace vessel was achieved at 80 degrees C in 30 min. A DB-624 capillary chromatographic column (60 m x 0.

Simultaneous determination of pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls and phthalate esters in human adipose tissue by gas chromatography-tandem mass spectrometry.

This paper describes a method for the simultaneous determination of 284 environmental contaminants, including 57 pesticides, 15 polycyclic aromatic hydrocarbons (PAHs), 209 polychlorinated biphenyls (PCBs) and 3 phthalate esters (PAEs), in adipose tissue samples. For the first time, a gas chromatography-tandem mass spectrometry (GC-MS/MS) method following a homogenised extraction using acetonitrile and purification by gel permeation chromatography (GPC) was used. Various performance characteristics, such as the limit of detection (LOD), limit of quantification (LOQ), linear range, recovery and precision, were determined for each analyte.

High-throughput GC/MS and HPLC/MS/MS techniques for the multiclass, multiresidue determination of 653 pesticides and chemical pollutants in tea.

An efficient and sensitive method has been established for simultaneous determination of 653 pesticides in teas by GC/MS and HPLC/MS/MS. The method involved extraction with acetonitrile followed by cleanup using Cleanert-TPT SPE and subsequent identification and quantitation of 490 pesticides by GC/MS and 448 pesticides by HPLC/MS/ MS. The LODs for pesticides determined by GC/MS were between 1.

Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China.

This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n=633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results showed that POPs pesticides were frequently detected, including 2,4'-DDD, 2,4'-DDE, 2,4'-DDT, 4,4'-DDD, 4,4'-DDE, 4,4'-DDT, α-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene (HCB), and mirex.

[Rapid determination of 3 nitromidazole residues in honey using liquid chromatography-tandem mass spectrometry].

A method was developed for the rapid determination of 3 nitromidazole residues in honey, including metronidazole, ronidazole and dimetridazole, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The honey sample was dissolved in water, and the solution was cleaned up with an Oasis HLB cartridge. The cartridge was washed with water and methanol-water solution (1:9, v/v) in turn, and eluted with ethyl acetate.

Levels of polychlorinated biphenyls in human adipose tissue samples from southeast China.

This paper presents a comprehensive study of polychlorinated biphenyl (PCB) levels and homologue profiles in human adipose tissues among residents of Southeast China. A large number of samples (n = 303) were selected for a number of PCB congeners (n = 62) which were analyzed by highly sensitive gas chromatography-tandem mass spectrometry (GC-MS/MS). The total mean PCB concentrations were 27.

[Determination of levamisole residue in milk and milk powder by ultra performance liquid chromatography-tandem mass spectrometry].

A sensitive and selective method is presented for the determination of levamisole residues in milk and milk powder by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Levamisole in the test samples was extracted with ethyl acetate under alkaline condition, then transferred into dilute hydrochloric acid, and cleaned-up with a strong cation exchange (SCX) column to obtain an extract suitable for the analysis by UPLC-MS/MS. Levamisole was separated by a BEHC18 UPLC column and acetonitrile-1.

Analysis method study on 839 pesticide and chemical contaminant multiresidues in animal muscles by gel permeation chromatography cleanup, GC/MS, and LC/MS/MS.

The paper reports the study of gel permeation chromatography (GPC), gas chromatography/mass spectrometry (GS/MS), and column chromatography tandem MS (LC/MS/MS) for 839 pesticides and chemical contaminants, through which a GPC data bank has been established for 744 pesticides, a GC/MS data bank for 541 pesticides, and an LC/MS/MS data bank for 464 pesticides. On the basis of this study, a new method for quantitative determination of 587 pesticide residues in animal muscles such as beef, mutton, pork, chicken, and rabbit has been established using GPC cleanup followed by GC/MS and LC/MS/MS. In the method, 10 g animal samples were mixed with 20 g sodium sulfate and extracted twice with 35 mL cyclohexane-ethyl acetate (1 + 1) by blender homogenization followed by centrifugation, filtration, and concentration.

Determination of residues of 446 pesticides in fruits and vegetables by three-cartridge solid-phase extraction-gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.

A method was developed for determination of residues of 446 pesticides in fruits and vegetables through the use of cleanup by a 3-cartridge solid-phase extraction-gas chromatography/ mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Fruit and vegetable samples (20 g) were extracted with 40 mL acetonitrile, salted out, and centrifuged. Half of the supernatant was passed into an Envi-18 cartridge, eluted with acetonitrile, and cleaned up with Envi-Carb and aminopropyl Sep-Pak cartridges in series after concentration of the eluates.

Validation study on 660 pesticide residues in animal tissues by gel permeation chromatography cleanup/gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.

A new method using gel permeation chromatography (GPC) cleanup followed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) has been established for quantitative determination of 437 pesticide residues in animal tissues such as beef, mutton, pork, chicken, and rabbit. Based on an appraisal of the characteristics of both GC-MS and LC-MS-MS, validation experiments were conducted for 660 pesticides. In the method, 10 g animal samples were mixed with 20 g sodium sulfate and extracted with 35 mL of cyclohexane+ethyl acetate (1+1) twice by blender homogenization, centrifugation, and filtration.

Simultaneous determination of 405 pesticide residues in grain by accelerated solvent extraction then gas chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry.

A new method has been established for simultaneous determination of 405 pesticide residues in grain, using accelerated solvent extraction (ASE), solid-phase extraction (SPE), and GC-MS and LC-MS-MS. The method was based on appraisal of the GC-MS and LC-MS-MS characteristics of 660 pesticides, their efficiency of extraction from grain, and their purification. Samples of grain (10 g) were mixed with Celite 545 (10 g) and the mixture was placed in a 34-mL cell of an accelerated solvent extractor and extracted with acetonitrile in the static state for 3 min with two cycles at 1,500 psig and at 80 degrees C.

Simultaneous determination of 16 sulfonamides in honey by liquid chromatography/tandem mass spectrometry.

A method is described for the determination of 16 sulfonamides in honey. Samples are dissolved in phosphoric acid solution (pH2), cleaned up with 2 solid-phase extraction (SPE) cartridges, an aromatic sulfonic cation-exchange cartridge and an Oasis HLB SPE cartridge, and analyzed both qualitatively and quantitatively by liquid chromatography/tandem mass spectrometry (LC/MS/MS) under the selected conditions. Without exception, calibration curves were linear (r = > 0.

Evaluation of analyte stability and method ruggedness in the determination of streptomycin residues in honey by liquid chromatography with post-column derivatization.

This study demonstrated that streptomycin in honey is quite stable, and the results showed no obvious differences for 3 samples containing incurred analyte during continuous testing for 4 months. Fifteen laboratories evaluated method performance at 4 fortification levels ranging from 0.010 to 0.

Determination of clopidol residues in chicken tissues by liquid chromatography: collaborative study.

Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.