BS ISO 20647 pdf free download

BS ISO 20647:2015 pdf free download.Infant formula and adult nutritionals – Determination of total iodine – Inductively coupled plasma mass spectrometry (ICP-MS).
3.7 Purified water, 18 Ml/cm.
3.8 Reference standards
3.8.1 Iodide standard solution in water, mass concentration p = 1 000 tg/m1, SPEX CertiPrep1).
3.8.2 Iodide standard solution in 1 % triethylamine (TEA), p = 1 000 tg/mI, Inorganic Venturesl).
3.8.3 Standard Reference Material (SRM), National Institute of Standards and Technology (NIST) SRM
1849a, Infant/Adult Nutritional Formula.
Either stock iodide reference solutions may be used for intermediate and working standard solutions preparation. The remaining source may be used as a continuing calibration verification (CCV) standard. Equivalent reference standards may be substituted. ‘Iodide’ may be referred to as ‘iodine throughout this International Standard.
3.9 Internal standards
3.9.1 Praseodymium (Pr) standard solution in 5 % HNO3, p = 10 tg/ml, Inorganic Ventures1).
Individual values of iodine are reported for each test sample using praseodymium as the internal standard. Equivalent stock internal standard solutions may be substituted.
3.10 Preparation of reagent solutions
3.10.1 General
Prepare all reagent solutions as recommended by either mass per volume or volume per volume. Adjusting for purity and/or concentration is not required.
3.10.2 KOH solution,p = 50 g/l
Dissolve 25 g of KOH pellets in an appropriate amount of purified water, then dilute to 500 ml with purified water. This solution may be added using a re-pipet volumetric bottle top dispenser. Store this solution at room temperature. Reagent expires 6 months after preparation date.
3.10.3 Stabilizer concentrate
Dissolve 5 g of Na2S2O3 in an appropriate amount of purified water, add 50 ml of NH4OH, then dilute to 500 ml with purified water. The resulting concentration is 10 % NH4OH and 1 % Na2S2O3 in purified water. Store this solution at room temperature. Reagent expires 6 months after preparation date.
3.10.4 Wash solution (rinse)
Dissolve 2 g of surfactant (3A) in an appropriate amount of purified water, add 20 ml of NH4OH, then dilute to 2 000 ml with purified water. The resulting concentration is I % NH4OH and 0,1 % surfactant in purified water. This solution may be added using a re-pipet volumetric bottle top dispenser. Store this solution at room temperature. Reagent expires 6 months after preparation date.
3.10.5 Diluent
Dissolve 10 g of KOH pellets and 0,4 g Na2S2O3 in an appropriate amount of purified water, add 4 ml NH4OH, then dilute to 2 000 ml with purified water. Store this solution at room temperature. Reagent expires 6 months after preparation date.
Alternatively, for a smaller volume, dilute 50 ml of 5 % KOH and 10 ml of stabilizer concentrate (3.10.3)
to 500 ml with purified water. The resulting concentrations for both preparations are 0,5 % KOH, 0,2 %
NH4OH, and 0,02 % Na2S2O3 in purified water. Store this solution at room temperature. Reagent expires
6 months after preparation date.
3.10.6 Conditioning solution
Prepare by aliquoting 25 ml of KO[I solution (3.10.2), then dilute to 250 ml with purified water. Use this solution to prepare the instrument for analysis. The resulting concentration is 5 g/l KOH. Store this solution at room temperature. Reagent expires 6 months after preparation date.
3.10.7 Carrier solution
This solution is equivalent to the wash solution (3.10.4). The carrier solution is used to deliver the sample solution to the nebulizer through the ICP-MS autosampler introduction system. The carrier solution is introduced via a peristaltic pump using 0,76 mm inside diameter (id) two-stop polyvinyl chloride pump tubing. Store this solution at room temperature. Reagent expires 6 months after preparation date.
3.11 Preparation of standard solutions
3.11.1 General
Stock solutions are stable until the end date indicated on the certificate of analysis. Intermediate stock standard, calibration standard, continuing calibration verification and internal standard solutions are stable at room temperature until the earliest expiration date of all components used to prepare the solution. These solutions are ready to use for analysis. Do not subject them to any of the various procedures used to prepare actual samples (i.e. infant formulas and adult nutritionals) for analysis.
3.11.2 Stock iodine and praseodymium solutions
Purchase of stock iodine and praseodymium standard solutions with accompanying certificates of analysis is recommended.BS ISO 20647 pdf download.