ABSTRACT
Objective@#To optimize the determination of pentachlorophenol in wooden chopping boards through pretreatment of miniaturized samples.@*Methods@# The pretreated wooden chopping board samples were subjected to ultrasound extraction (1 mL of 0.5 mol/L K2CO3 added in 5 mL extraction solution) in 8 mL acetone and 2 mL water, followed by derivatization with 0.3 mL acetic anhydride, extraction with n-hexane and separation with DB-5ms column (30 m×0.25 mm, 0.25 μm). Gas chromatography tandem mass spectrometry (GC-MS/MS) was performed in multiple reaction monitoring (MRM) mode with quantitative analysis using the internal standard method.@*Results@#The GC-MS/MS assay showed a good linear relationship within the range of 0.01 to 0.2 µg/mL (R2>0.999), with a 0.003 mg/kg limit of detection and 0.01 mg/kg limit of quantitation. The mean recovery rates were 84.2% to 96.7% at spiked concentrations of 0.003, 0.01 and 0.03 mg/kg, with relative standard deviation of 2.2% to 6.1%.@*Conclusions@#The established GC-MS/MS assay is easy to perform, environment-friendly, highly accurate and sensitivity, which is feasible for determination of pentachlorophenol in wooden chopping boards.
ABSTRACT
OBJECTIVE: To develop a simple, fast and sensitive analytical method based on isotope dilution-headspace gas chromatography-mass spectrometry for the determination of 1, 4-dioxane residue in the aerosol cosmetics. METHODS: Sample was successive weighed and dissolved in 1, 3-dimehyl-2-imidazolidinone(DMI)solvent and isotope internal standard was added. Then transfered to a 20 mL headspace vial. The headspace vial was sealed and extracted 15 min by ultrasonic-assisted extraction. After separated by HP-5 MS fused silica capillary column(30 m×25 mm, 0. 25 µm), the compound was analyzed by gas chromatography-mass spectrometry in selected ion monitoring mode(GC-MS-SIM) and quantified by internal standard method. RESULTS: There were good linear correlations with R~2 no less than 0. 999 in the range of 1. 0-100 mg/kg. The limit of detection(LOD) of this method was 0. 3 mg/kg. At 0. 3, 1. 0, 5. 0 and 30 mg/kg four added concentration, recovery for five kinds of aerosol cosmetic were all between 91. 4% and 104. 2%. The relative standard deviations(RSDs) were 1. 5%-6. 3% and 1. 7%-6. 4%(n=6), respectively. CONCLUSION: The developed method has proved convenient, time-saving, accurate and sensitive and suited for determination 1, 4-dioxane in aerosol cosmetic.
Subject(s)
Cosmetics/analysis , Aerosols , Dioxanes , Gas Chromatography-Mass Spectrometry , Mass SpectrometryABSTRACT
A rapid method for the simultaneous screening and detection of ten anticoagulant rodenticides in foods was developed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). After the extraction by acetonitrile and clean-up by QuEChERS, the extract was separated on a Poroshell 120 EC-C18 column (100 mm x 2.1 mm, 2.7 microm) with the gradient elution of 5 mmol/L ammonium acetate and acetonitrile. The detection was carried out by UPLC-MS/MS using a negative electrospray ionization interface in multiple reaction monitoring (MRM) mode. The ten anticoagulant rodenticides showed a good linear relationship (r > 0.99) in the range of 5 - 500 microg/L. In the four samples of chili sauce, flour, vinegar and soy sauce, the spiked recoveries were in the range of 72.6% - 112%, and the relative standard deviations (RSD) were all not more than 11.2%. The limits of detection (LOD) were all in the range of 0.5 - 4.5 microg/kg. This method is rapid, simple, sensitive, accurate and of good specificity for the satisfactory rapid screening and detection of the ten anticoagulant rodenticides in the sudden public health security events.
Subject(s)
Food Contamination/analysis , Rodenticides/analysis , Tandem Mass Spectrometry , Anticoagulants/analysis , Chromatography, High Pressure LiquidABSTRACT
A method for the simultaneous determination of 34 pesticides in rice, proso millet and wheat by QuEChERS coupled with on line gel permeation chromatography-gas chromatography-mass spectrometry (GPC-GC-MS) was developed. The effects of the sample weight, extraction solvent, sorbent for purification were investigated. The matrix effect and the usefulness of analyte protectant were also studied. The identification and quantification were performed by GPC-GC-MS in selected ion monitoring (SIM) mode and exrternal standard method. The calibration curves of the 34 pesticides showed good linearity in th range of 0.0125-0.2 mg/L with thea correlations coefficients (r2) between 0.968 and 0.999. The average recoveries were 94.5%-117.1%, 83.1%-121.7% and 93.1%-120.2% with the relative standard deviations (RSDs, n = 6) no more than 14.5%, 15.1% and 15.2% in rice, proso millet and wheat samples, respectively. The LODs of this method were 0.0281-5.31, 0.0282-4.82 and 0.0273 -5.13 microg/kg (S/N = 3) for rice, proso millet and wheat samples, respectively. The low cost and less consumption of reagents of this method are in accordance with the concept of green chemistry. The convenient operation and versatility of this method are suitable for the fast screening and detection of the 34 pesticide residues in rice, proso millet and wheat.
