Reagecon's Thulium Standard 1000 µg/mL (1000 ppm) in 2-5% HNO for ICP or ICP-MS is manufactured from ultra-pure metal (99.999%) and it is tested by an ISO17025 Accredited Test Method (INAB Ref: 264T). The raw material used in this standard is assayed by titration and ICP-MS prior to manufacture. Separate standards are used to control or calibrate the titration and ICP-MS respectively. 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 as specification of ± 0.2%. The results are reported in mg/kg and mg/L on the basis of weight and density. Reagecon hold ISO/IEC 17025 accreditation for calibration of laboratory balances (INAB Ref: 265C). All of the volumetric, titrimetric and gravimetric functions are carried out under a highly regulated temperature regime. Reagecon hold ISO/IEC 17025 for Temperature Calibration in the range of -90 C to 650 C (INAB Ref: 265C) and ISO/IEC 17025 Accreditation for density measurement using Oscillating U-Tube and Bingham Pycnometry Methods (INAB Ref: 264T). - GHS/OSHA compliant, REACH - This product is produced in a highly controlled cleanroom (ISO 7) environment, using ultra-pure water (specially treated for the production of mass spectroscopy standards), triple distilled acids and triple leached pre-cleaned bottles. The titrimetry and spectroscopy are controlled and calibrated using separate standards, so the product comes with two layers of traceability including NIST Standards, where available. All of the uncertainties of measurement for this product are calculated according to Eurachem/CITAC guidelines and reported as expanded uncertainties at the 95% confidence level.