Calibration standard (ng/ml)	10	50	100	200	500
Metal	10	50	100	200	500
Pb	10	50.914	100.113	202.038	498.658
Zn	10	48.914	93.605	196.051	498.790
Cu	10	50.893	98.404	203.210	499.146
Cd	10	50.120	99.280	201.541	499.515