ABSTRACT
Objective To develop an analytical method by gas chromatograph-mass spectrometry(GC-MS) for the determination of organic chloride pesticides and polycyclic aromatic hydrocarbons in prophyra Methods The samples were extracted by an acetone-hexane(7∶3,V/V) mixture first,then were purified by C18 solid-phase extraction(SPE),and then were determined with GC-MS.Results The linear range was 0.01-5.0 ?g/ml,the limits of detection were 0.05-0.32 ng/g(dry weight) and 0.25-0.56 ng/g(dry weight)for organic chloride pesticides and polycyclic aromatic hydrocarbons respectively.The recovery rates and relative standard deviation for organic chloride pesticides were 74.27%-121.49% and 3.19 %-17.31% relatively;the recovery rates and relative standard deviation for polycyclic aromatic hydrocarbons were 65.10%-119.26% and 2.75%-14.11% relatively.Organic chloride pesticides were partly detected,but the detection rate of polycyclic aromatic hydrocarbons was higher.Fifteen polycyclic aromatic hydrocarbons were detected in all samples but dibenz(a,h)-anthracene.Conclusion This method is sensitive,accurate and applicable to the determination of organic chloride pesticides and polycyclic aromatic hydrocarbons in prophyra.
ABSTRACT
Objective: In this paper, a method of gas chromatography mass spectrometry for determination of free resveratrol in grape wine was established. Methods: After evaporated to eliminate ethanol, sample of grape wine was extracted with ethyl acetate, and evaporated again to dryness. The residues were derivatized with N,O bis (trimethylsianyl) trifluoroacetamide plus 1% trimethychlorosilane. Then, qualitative and quantitative analysis of cis and trans resveratrol were carried out using GC MS scan mode. Results: The average recoveries were 85.6%-110.5%,and the relative standard deviations were 8.2%-11.5%, when resveratrol was added to grape wine at 0.25-1.25 mg/L levels. The correlation coefficient was 0.995 in range of 0.50-10.00 mg/L. The detection limit for resveratrol in grape wine was 0.005 mg/L. Further 15 grape wines made in China were analyzed. The contents of cis resveratrol were 0.02 -0.56 mg/L and trans resveratrol were 0.15-1.28 mg/L. Total resveratrol were 0.26-1.48 mg/L. Conclusion: This assay is accurate and reproducible for determination of free resveratrol in grape wines.