Determination of 22 Triazole Compounds Including Parent Fungicides and Metabolites in Apples, Peaches, Flour, and Water by Liquid Chromatography/TandemMass Spectrometry

Abstract A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed for the determination of 14 parent triazole fungicides and 8 of their metabolites found in apples, peaches, flour, raw water, and tap water. The triazole fungicides chosen for this multiresidue method development project included propiconazole, fenbuconazole and its RH-9129 and RH-9130 metabolites, cyproconazole, difenoconazole, tebuconazole and its HWG 2061 metabolite, hexaconazole, bromuconazole (both stereoisomers), epoxiconazole, tetraconazole, triticonazole and its RPA-404886 and RPA-406341 metabolites, triadimefon, triadimenol, and myclobutanil. Of special concern to the U.S. Environmental Protection Agency were the metabolites common to all triazole fungicides: free triazole, 1,2,4-triazole (T), and its 2 conjugates: triazolylalanine (TA) and triazolylacetic acid (TAA). These metabolites were the primary focus of this project. All samples we cleaned up by a combination of C18 solid-phase extraction (SPE), mixed-mode cationic SPE, and mixed-mode anionic SPE columns. A triple-stage quadrupole mass spectrometer, equipped with electrospray ionization in the positive-ion mode, was used to determine the compounds of interest. T, TA, and TAA were quantitated using isotopically labeled internal standards (IS), in which the 1,2,4-triazole ring had been synthesized by using 13C and 15N (IS_T, IS_TA, and IS_TAA). These isotopically labeled internal standards were necessary to correct for matrix effects. The T, TA, and TAA metabolites were quantitated at the 25–50 parts-per-billion (ppb) level in food commodities and at 0.50 ppb in water. Recoveries were 70–101% from apples, 60–121% from peaches, 57–118% from flour, 75–99% from raw water, and 79–99% from tap water.

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Bioanalytical method development and validation of simultaneous analysis of telmisartan and hydrochlorthiazide in human plasma using LC-MS/MS

International Journal of Bioassays ◽

10.21746/ijbio.2016.03.003 ◽

2016 ◽

Vol 5 (03) ◽

pp. 4862 ◽

Cited By ~ 1

Author(s):

Mathew George* ◽

Lincy Joseph ◽

Arpit Kumar Jain ◽

Anju V.

Keyword(s):

Human Plasma ◽

Retention Time ◽

High Performance ◽

Method Development ◽

Matrix Effects ◽

Solid Phase ◽

Internal Standard ◽

Assay Method ◽

Buffer System ◽

Internal Standards

A simple, sensitive, rapid and economic high performance thin layer chromatographic method and a mass spectroscopic assay method has been developed for the quantification of telmisartan and hydrochlorthiazide combination in human plasma. The internal standards and analytes were extracted from human plasma by solid-phase extraction with HLB Oasis1cc (30mg) catridges. The scanning and optimization for the samples are done using methanol: water (50:50). The samples were chromatographed using reverse phase chromatography with C-18 column of different manufacturers like Ascentis C18 (150×4. 6, 5µ) using the buffer system Acetonitrile: Buffer (80:20%v/v) which consist of 2±0. 1Mm ammonium format at a flow rate of 0. 7ml/min at a column oven temperature 35±10c. The internal standard used was hydrochlorthiazide13c1, d2 and telmisartand3. The extraction techniques include conditioning, loading, washing and elution, drying followed by reconstitution of the dried samples. The volume injected was 10µl with the retention time of 3-4 min for telmisartan, 1-2 min for hydrochlorthiazide and for the internal standards the retention time was 3-4 min for telmisartand3 and 1-2 min for hydrochlorthiazide c13d2. The rinsing solution was Acetonitrile: HPLC grade water in the ratio (50:50). The above developed method was validated using various parameters like selectivity and sensitivity, accuracy and precision, matrix effects, % recovery and various stability studies. The method was proved to be sensitive, accurate, precise and reproducible. The preparation showed high recovery for the quantitative determination of telmisartan and hydrochlorthiazide in human plasma.

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Determination of 12 Carbamate Insecticides in Typical Vegetables and Fruits by Rapid Multi-Plug Filtration Cleanup and Ultra-Performance Liquid Chromatography/Tandem Mass Spectrometry Detection

Journal of Chromatographic Science ◽

10.1093/chromsci/bmz081 ◽

2019 ◽

Vol 58 (2) ◽

pp. 109-116

Author(s):

Lili Ma ◽

Liuwei Zhao ◽

Jiaqi Wang ◽

Canping Pan ◽

Cong Liu ◽

...

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Matrix Effects ◽

Solid Phase ◽

Ultra Performance Liquid Chromatography ◽

Tandem Mass ◽

Liquid Chromatography Tandem Mass ◽

Vegetables And Fruits

Abstract A multiresidue method for determining 12 carbamate pesticides in purple cabbage, orange, watermelon, cucumber, cowpea and Lactuca sativa L. employing multi-plug filtration cleanup (m-PFC) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. M-PFC was carried out by cleanup at dispersive solid phase extraction (d-SPE), one m-PFC tip-filtration, two m-PFC tip-filtration and other methods (1–3 m-PFC cleanups). Results demonstrated that filtration simplified the cleanup method compared with d-SPE and other m-PFC methods (1–3 m-PFC cleanups). The method validation results showed that the method was linear, selective and accurate. The limits of quantification (LOQs) were 0.05–5.0 μg/kg, and the recoveries were in the range of 70.1–119.9% in different matrices. Although matrix effects were observed, they were successfully compensated using matrix-matched calibration. Finally, the developed method was successfully applied to detect pesticides in real samples.

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Direct Determination of Glyphosate and its Metabolite AMPA in Soil Using Mixed-Mode Solid-Phase Purification and LC-MS/MS Determination on a Hypercarb Column

Journal of AOAC International ◽

10.5740/jaoacint.18-0287 ◽

2019 ◽

Vol 102 (3) ◽

pp. 952-965 ◽

Cited By ~ 2

Author(s):

Pei Zhang ◽

Mick Rose ◽

Lukas Van Zwieten

Keyword(s):

Mixed Mode ◽

Crop Production ◽

Solid Phase ◽

Direct Determination ◽

Correlation Coefficients ◽

Grain Production ◽

Internal Standards ◽

Aminomethylphosphonic Acid ◽

Lc Tandem Ms

Abstract Background: Although glyphosate is widely used in agriculture, information on its residue level in soils remains scarce partly because of the difficulty in its analysis. Objective: Develop and validate a method to directly analyze glyphosate and its metabolite aminomethylphosphonic acid (AMPA) in soil. Method: Soils were extracted with 0.6 M KOH solution, and coextracted interferences were removed using a mixed-mode Bond Elut Plexa PAX®. The extracts were analyzed by LC-tandem MS fitted with a Hypercarb column and isotope-labeled (13C,15N) glyphosate and AMPA were used as internal standards. Results: LOQs were 0.05 mg/kg for both glyphosate and AMPA in soils. Correlation coefficients were ≥0.99, residuals were below 20%, and calibrations were linear in the range 0.02–1.0 μg/mL. The method was validated on five contrasting soils (Vertosol, Calcarosol, Chromosol, Sodosol, and Tenosol) commonly used for grain production in Australia. The recoveries for glyphosate and AMPA in the soils were 96–121 and 91–118%, respectively, with RSD in the range of 3–16%. Conclusions: This paper presents using the validated method in analysis glyphosate and AMPA in soils collected from crop production paddocks in Australia. The survey data showed that glyphosate and AMPA were detected in all collected soils, with concentrations ranging between 0.05 and 1.2 mg/kg. Highlights: The study demonstrates that the mixed-mode solid-phase extraction is effective in removing interferences and validates the use of Hypercarb as an alternative stationary phase for glyphosate and AMPA analysis from soils.

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