GC/TOF-MS를 이용한 다(茶)류 중 잔류농약 동시다성분 분석법 연구

Abstract

A method for determination of 166 pesticides including acrinathrin in teas using GC/TOF-MS has been established and validated. One hundred forty eight tea samples were purchased from local markets and monitored for pesticides. The good linearity, low limit of detection(LOD) and quantification(LOQ) were obtained by the established method for 166 pesticides. The linear regression coefficients(R2) of the pesticides were higher than 0.99, except for captapol(=0.97856), cycloprothrin(=0.82121), fen -pyroximate(=0.91392), and molinate(=0.98405). LODs of the pesticides ranged 0.13～20 ppb, except for pyraclofos(=38.88 ppb), azinphos-methyl(=40.81 ppb), and captafol(58.65 ppb). LOQs of the pesticides ranged 0.44～54.59 ppb, except for folpet(62.55 ppb), deltamethrin(66.67 ppb), pyraclofos(129.60 ppb), azinphos-methyl(136.04 ppb), and captafol(195.50 ppb). The pesticides were recovered in the range of 71.12～108.8% with relative standard deviation(RSD) range of 5.13～12.31%. RSDs of intra-assay precision and intermediate precision at two different fortified levels of concentration were in the range of 2.02～6.27% and 3.08～10.11%, respectively. Therefore, ther recovery and precision of analysis method were quite good for the test pesticides. A total of 148 samples in four kinds of teas including 90 green teas, 20 black teas, 20 oo-long teas and 12 puer teas were investigated. Within the samples tested, the pesticides were detected in 32 samples. and most frequently in the green teas(27 of 90 ; 22 original green teas, 3 processed green teas, 2 brown rice flavored green teas). The pesticides were also detected in the 2 oo-long teas and the 1 black teas. Among 27 teas contaminated with pesticides, there were 25 from china, and 2 from Korea. There were two puer teas contaminated with pesticides. One was produced in China, the other was produced in Taiwan. The black teas contaminated with pesticides were produced in India. Among the pesticides detected, there were 13 pesticides not to meet MRLs, which were detected ten times in 27 green teas, one time in 2 puer teas, and two times in 2 oo-long teas. In the green teas, the concentrations of pesticides detected in 10 of the 27 green teas were higher than MRL. and the pesticides were dicofol (seven times detected in seven samples), mepronil (one time detected in one sample), fenazaquin (two times detected in two samples), endosulfan sulfate (two times detected in two samples), ethion (three times detected in three samples), β-endosulfan (two times detected in two samples) and fenpropathrin (one time detected in one sample). All the green teas produced in China were contaminated with higher levels than MRLs for pesticides. One of two Taiwan puer teas contaminated with pesticides showed higher levels than MRL for ethion. the pesticides found in two Chines oo-long teas monitored were dicofol(two times detected), β-endosulfan(two times detected), and endofulfan sulfate(one time detected). Among 13 pesticides founded in samples tested, Korea has not established MRLs for the pesticides but two pesticides (chlorfenapyr and chlorpyrifos). The pesticides which did not meet the MRLs have not been limited by MRLs in teas. Therefore, it should be a priority for regulatory agency to establish MRLs for pesticides which do not have MRLs in Korea. And also, it is necessary to extend the number of pesticides which have MRLs up to 200 pesticides, and establish positive list. This study recommend to change the analytical technique for detecting pesticides to GC/TOF-MS to save labour, time, economic costs and so on. The safety of teas can be more secured by this study which can applied to make food policy for teas.