High-Purity Standards.....manufactures single and multielement standards of extremely high purity for the calibration of analytical instruments such as the AAS, ICP, ICP-MS, Ion Chromatography and CNS elemental analysis. HPS welcomes requests for custom made mixtures from nanogram to milligram concentrations. We would be pleased to quote you a price for a standard that meets your own laboratory needs. Certified Reference Materials such as drinking water, waste water, sea water, soils, sludges, biological products, foods, and air filters are available for Quality Control and method development.