Reagecon’s Calcium Standard for ICP; ICP-MS 10;000 µg/mL (10;000 ppm) in 2-5% Nitric Acid (HNO₃) for ICP or ICP-MS is manufactured from ultra-pure metal (99.999%). This product is manufactured gravimetrically using the mass balance approach: 100% less the sum of all impurities (w/w). Prior to bottling; the final product is tested and verified using ICP-MS and is reported using the gravimetric result; corrected for density. To a specification of ± 0.2%. The results are reported in mg/kg and mg/L on the basis of weight and density. Reagecon hold ISO 17025 accreditation (A2LA Ref: 6739.02) for calibration of laboratory balances.