Tang Gangling

同位素内标-UPLC-MS/MS法测定烟草中的9种常见农药残留

为快速测定烟草中的农药残留，建立了烟草中9种常见农药残留的同位素内标-UPLC-MS/MS检测方法。以农药的氘代物为内标，样品经乙腈提取后，以N-丙基乙二胺（PSA）分散固相萃取净化，以BEH C18色谱柱进行分离，通过多反应离子监测模式（MRM）进行定性和定量分析。结果表明：① 各农药在12.5~500 ng/mL范围内呈良好的线性关系，相关系数>0.998。② 各农药残留的检出限（LOD）为0.003~0.009 mg/kg，定量限（LOQ）为0.011~0.030 mg/kg；空白样品在0.25~1.00 μg/g范围内3个加标水平的平均回收率为85.5%~110.1%，相对标准偏差 < 6.0%。③ 对30个实际样品测定发现，与空白基质匹配标准校正法相比，同位素内标法的结果一致，但操作简便。该方法适用于烤烟、白肋烟和香料烟等烟草及烟草制品中9种农药残留的检测。

Determination of Pentachlorophenol in Papers for Cigarette Product by LC-MS/MS Method

A method based on high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for determining the pentachlorophenol in cigarette papers. The sample of paper was ultrasonically extracted, the extract was directly injected into and separated on an Atiantis d C18 column by using methanol-water(containing 0.1% formic acid) as mobile phase. The pentachlorophenol was detected by LC-MS/MS under multiple reaction monitoring(MRM) mode and quantified by internal standard method. The results showed that: 1) The linear range and quantification limit of this method were 1-20 ng/mL and 0.018mg/kg, respectively. The linear relation was good(R20.99). The average recoveries were more than 91.6% with the relative standard deviations less than 8%. 2) This method was suitable for the fast analysis of pentachlorophenol in papers for cigarette product with the advantages of simple pretreatment and free of complex derivation steps.

Uncertainty in Determination of Total Alkaloids in Flue-cured Tobacco with Continuous Flow Method

In order to evaluate the uncertainty in the determination of total alkaloids in flue-cured tobacco with continuous flow method,the cause-effect relationship diagram in the determination was revised and a new mathematical model for measurement uncertainty assessment was set up by analyzing the whole measurement process.The sources of measurement uncertainty,sample concentration and measurement repeatability of autoanalyzer were determined.The results showed that: the measurement uncertainty mainly come from the moisture content in sample.The standard uncertainty of measurement results was 0.05%,and the expanded uncertainty(α=0.05,k=2) was 0.10%.

Determination of Maleic Hydrazide Residue in Tobacco and Tobacco Products with High Performance Liquid Chromatography

A method for the determination of maleic hydrazide(MH)in tobacco and tobacco products was established,in which MH in tobacco sample was extracted with a solvent,and cleaned up by a solid phase extraction cartridge,then detected with high performance liquid chromatography.The residue of MH in 23 tobacco samples was determined.The results showed that: 1)Good results were obtainable when tobacco sample was extracted with 4 mol/L hydrochloric acid under heating and refluxing for 1 hour.2)The MH peak was completely separated from impurity peaks in 20 minutes by reversed-phase HPLC with a Varian Microsorb-MV 100-5 C18 column under isocratic elution with 0.1 mol/L acetic acid as mobile phase at a flow-rate of 0.7 mL/min.3)The recovery of MH was 97.11% with the relative standard deviation(RSD)of 7.13%.This method is suitable for the determination of MH in tobacco and tobacco products.

Determination of Dithiocarbamate Pesticide Residues in Tobacco by Gas Chromatography-Mass Spectroscopy

A method was presented for the analysis of dithiocarbamate pesticide residues in tobacco,in which tobacco was put into a closed-conical flask,the residues of dithiocarbamate pesticides in tobacco were extracted and hydrolyzed to CS2 under ultrasonic conditions,then CS2 trapped in a layer of iso-octane overlaying the reaction mixture was taken for gas chromatography-mass spectroscopy analysis.The recoveries ranged from 90.4% to 106.0% with the relative standard deviations(RSD) of 3.2% to 9.5% and the limit of quantification(LOQ) of 0.017 mg/kg.This method can be used for the fast analysis of the dithiocarbamate pesticide residues in tobacco.

Transfer of 29 Organophosphorus Pesticides in Cut Tobacco to Particulate Matter in Mainstream Cigarette Smoke and Cigarette Butt

29 organophosphorus pesticides were added into the test cigarettes,the transfer rates of these pesticides to the particulate matter ( PM) in mainstream cigarette smoke and cigarette butts were determined with gas chromatography/mass spectrometry. The results indicated that the average transfer rates to PM in MCS was 0-6. 3% with the relative standard deviations ( RSDs) of 8. 0% -18% and the average retention rate of cigarette butts was 0. 3% -15% with the RSDs of 6. 5% -21% .

Determination of Lead Isotope Ratios of Tobacco by ICP-MS and Their Areal Difference

The lead isotope ratios of 100 B1F tobacco samples from 100 areas of 10 provinces in China were determined by ICP-MS combining with HNO3-H2O2 microwave digestion and standard-sample-bracketing method. The results showed that the relative standard deviations of 207Pb/206Pb and 208Pb/206Pb for short-term measurements were 0.08% and 0.09%,respectively. The optimal concentration range of sample was from10 to 50 μg/L. The difference of lead isotope ratios between samples from the same province was relatively narrower,while that between samples from different provinces was obviously wider. The isotope ratios,207Pb/206Pb and 208Pb/206Pb,of tobacco sample could be used for comparing areal difference.

Study on Analyzing Residues of 22 Organophosphorus Pesticides in Tobacco

A method for simultaneously determining the residues of 22 organophosphorus pesticides in tobacco was developed with accelerated solvent extraction,solid-phase extraction and gas chromatography using isazophos as an internal standard.The results showed that the average recoveries of the pesticides ranged from 78.10% to 119.51% with RSDs of below 15%(n=6).This method is suitable to simultaneous determination of the residues of 22 organophosphorus pesticides in tobacco.