LabKings provides certified standard solutions for both Organics and Inorganics (traceable to NIST) use. These standard solutions are produced by an accredited laboratory according to ISO / IEC 17025 / 17034 (Guide 34) -A2LA-. Quality systems of the manufacturer is tested by NSF-ISR ISO registered (9001: 2008). All our standard solutions are provided with a Certificate of Analysis, shelf life 24 months. IV-STOCK-1643