Certified valuesAs. 18.3 µg/LFe .1.03 mg/LSe. 9.8 µg/LCd . 19.9 µg/LMn.103 µg/LZn . 1.00 mg/LCr .123 µg/LNi .108 µg/LCu . 309 µg/LPb .145 µg/L