Analysis of Heavy Metals and Pesticide Residues in Codonopsis Radix / 中国药房

ABSTRACT

OBJECTIVE:To establish a method for the determination of heavy metals and pesticide residues in Codonopsis Ra-dix to evaluate the safety of Codonopsis Radix commercially available in Taiyuan city. METHODS:Gas chromatography was used to determine the residues of organochlorine pesticides in Codonopsis Radix. The column was DB-1701 fused silica capillary col-umn,detector was 63Ni-ECD electron capture detector,carrier gas was high-purity nitrogen,volume temperature was 210℃,detec-tor temperature was 300 ℃ and volume injection was 1 μl. ICP-MS method was conducted to determine the contents of Pb,Cd, Hg and As. High frequency transmitter power was 1 500 W,temperature of premix chamber was 2 ℃,flow rate of cooling gas was 15.0 L/min,flow rate of carrier was 0.8 L/min,peristaltic pump speed was 0.1 ml/s,compensation flow rate was 0.3 L/min and volume depth was 8 mm. RESULTS:The linear range of organochlorine pesticides was 4-100 μg/L(r≥0.995 0). RSDs of pre-cision,stability and reproducibility tests were not higher than 13.7%,recovery was 97.0%-104.0%(RSD≤1.9%,n=9). Linear re-gression equations of Pb,Cd,Hg and As were 0~0.025、0~0.025、0~0.005、0~0.025 μg/ml(r≥0.999 2),respectively. RSDs of precision,stability and reproducibility tests were not higher than 9.3%,average recoveries was 95.0%-106.7%(RSD≤3.8%,n=9). CONCLUSIONS:The method is simple,sensitive and accurate,and can be used for the determination of heavy metals and parts of pesticide residues in Codonopsis Radix. The contents of heavy metals and organochlorine pesticide residues in Codonopsis Radix are comformed to national limits.