ISO 20633-2015 pdf free download

ISO 20633-2015 pdf free download.Infant formula and adult nutritionals Determination of vitamin E and vitamin A by normal phase high performance liquid chromatography
Form ules infan tiles et produits nutritionnels pour adultes — Determination de Ia teneur en vitamine E et de la teneur en vitamine A par chromatographie liquide a haute performance en phase normale.
4.15.2 Retlnyl acetate reference standard, primary reference standard. CAS 127-47-9.
4.15.3 a-tocopheryl acetate reference standard, primary reference standard. CAS 7695-91-2
4.15.4 a-tocopherol reference standard, primary reference standard. CAS 10191-41-0.
4.16 Standard solutions
4.16.1 Retinyl palmitate stock standard solution.
Weigh to the nearest 0,01 mg, approximately 70 mg of retinyl palmitate (415.1) into a 50 ml volumetric
flask (5jj). Dissolve in and dilute to volume with iso-octane (45).
4.16.2 Retlnyl acetate stock standard solution.
Weigh, to the nearest 0,01 mg, approximately 35 mg of retinyl acetate (4.15.2) into a 50 ml volumetric flask (5Jj). Dissolve in and dilute to volume with ethanol (4).
4.16.3 a-tocopheryl acetate stock standard solution.
Weigh, to the nearest 0,01 mg, approximately 180 mg of a-tocopheryl acetate (4.15.3) into a 50 ml volumetric flask (511). Dissolve in and dilute to volume with iso-octane.
4.16.4 a-tocopherol stock standard solution.
Weigh, to the nearest 0,01 mg, approximately 100 mg of a-tocopherol (4.15.4) into a 50 ml volumetric flask (511). Dissolve in and dilute to volume with iso-octane.
NOTE The above stock standard solutions are stable in a refrigerator at 4 °C to 8 °C for up to 7 days.
4.16.5 Combined working standard solution 1.
Transfer by pipette 4 ml of retinyl palmitate stock standard solution (4.16.1). 4 ml of retinyl acetate stock standard solution (4162), 7 ml of a-tocopheryl acetate stock standard solution (4.16.3) and 20 ml of a-tocopherol stock standard solution (41 A). into a 50 ml volumetric flask (51.1) and dilute to volume with iso-octane. Prepare this solution freshly prior to use.
4.16.6 Combined working standard solution 2.
Transfer by pipette 8 ml of combined working standard solution 1 (4.16.5) into a 100 ml volumetric flask (511) and dilute to volume with iso-octane. Prepare this solution freshly prior to use.
4.16.7 Calibration standard solutions
Into separate 50 ml volumetric flasks (SAl), transfer by pipette 0,5 ml, 2 ml, 4 ml, 8 ml, 16 ml and 32 ml of combined working standard solution 2 (4.lñ..6), and dilute to volume with iso-octane. These solutions are used to construct a multipoint calibration curve. Prepare these solutions daily prior to use.
NOTE For routine testing and depending on the concentration range of the analytes in the test samples, a
3 or 4 point standard curve can be used, provided the ranges are within the lowest and highest points of the 6
point curve listed above.
4.17 Stock standard purity determinations
4.17.1 Spectrometrlc purity of retinyl palmitate stock solution
Pipet 1 ml of retinyl palmitate stock standard solution (4J6.1) into a 100 ml volumetric flask (5.il)
and make up to volume with ethanol. Determine the absorption at 325 nm, zeroed against ethanol in a
1 cm quartz cell. Repeat the reading a further two times, rinsing the sample cuvette with the solution
before each reading. Calculate the average absorbance reading. Calculate the spectrometric purity as a
decimal, SPp, of retinyl palmitate using Formula (1):ISO 20633-2015 pdf free download.