ABSTRACT
OBJECTIVE:To establish a method for the residues determination of Pb,Cd,Cu,As and Hg in Codonopsis pilo-sula,and evaluate the quality evaluation of C. pilosula of Pingshun County in Shanxi province. METHODS:Microwave diges-tion-inductively coupled plasma mass spectrometry was adopted with KED scanning model,RF power was 1 550 W,sampling depth was 5.0 mm,plasma gas(argon)flow rate was 16.0 L/min,helium partial pressure was 0.1 mbar,argon gas was 0.6 mbar, the vacuum degree of 5×10-8 mbar,branch turbopump speed was 1 000 hz,sampling cone aperture was 1.0 mm,skimmer aperture was 0.5 mm,the spray chamber temperature was 2.7 ℃,the data collection was repeated 3 times. RESULTS:The linear range was 0-20 ng/ml for Pb(r=0.999 3),0-10 ng/ml for Cd(r=0.998 5),0-250 ng/ml for Cu(r=0.998 8),0-20 ng/ml for As(r=0.999 0) and 0-1.0 ng/ml for Hg(r=0.997 9);RSDs of precision,stability and reproducibility tests were lower than 3.0%;recoveries were 95.80%-100.20%(RSD=1.85%,n=6),94.50%-98.00%(RSD=1.26%,n=6),98.52%-102.43%(RSD=1.60%,n=6), 94.90%-98.70%(RSD=2.29%,n=6)and 96.00%-101.00%(RSD=1.84%,n=6);the limits of detection were 0.021 0,0.003 4, 0.043 7,0.115 6 and 0.005 6 ng/kg,respectively. Pb,Cd,Cu,and As were detetcted,and Hg was not detected,the range of total contents was 7.185 2~12.558 0 mg/kg. CONCLUSIONS:The method is simple with good precision,stability and reproducibility, and can be used for the residues determination of Pb,Cd,Cu,As and Hg in C. pilosula;heavy metal residues in C. pilosula in Shanxi Pingshun county does not exceed limit values of national and industry standards.