OMB Meeting Book_9-11-14

ISO/WD

5.19.3 Stock solution 3 – Polyunsaturated

Into a 100 mL accurately weigh ca. 25 mg of Linolelaidic acid methyl ester (C18:2 n-6 trans or Δ9,12 trans), 25 mg of Linoleic acid methyl ester (C18:2 n-6 cis or Δ9,12 cis), 25 mg of gamma-Linoleic acid methyl ester (C18:3 n-6 gamma or Δ9,12 cis), 25 mg of Linolenic acid methyl ester (C18:3 n-3 cis or Δ12,15 cis), 25 mg of cis-11,14- Eicosadienoic acid methyl ester (C20:2 n-6 cis or Δ11,14 cis), 25 mg of cis-8,11,14-Eicosatrienoic acid methyl ester (C20:3 n-6 cis or Δ8,11,14 cis), 25 mg of cis-11,14,17-Eicosatrienoic acid methyl ester (C20:3 n-3 cis or Δ11,14,17 cis), 50 mg of Arachidonic acid methyl ester (C20:4 n-6 cis or Δ5,8,11,14 cis), 25 mg of cis-13,16- Docosadienoic acid methyl ester (C22:2 n-6 cis or Δ13,16 cis), 25 mg of cis-5,8,11,14,17-Eicosapentanoic acid methyl ester (C20:5 n-3 cis or Δ11,14,17), and 25 mg of cis-4,7,10,13,16,19-Docosahexaenoic acid methyl ester (C22:6 n-3 cis or Δ4,7,10,13,16,19 cis). Make up to the mark with n-hexane. Into a 100 mL volumetric flask pipette 25,0 mL of the calibration standard stock solution 1 (5.19.1), 25,0 mL of the calibration standard stock solution 2 (5.19.2) and 25,0 mL of the calibration standard stock solution 3 (5.19.3). Then make up to the mark with n-hexane. Dilute accordingly to the type of injector used. NOTE This solution keeps for about six months if stored in the dark at -20° C. To prevent contamination of the standard solution, immediately distribute the solution into different vials (ready to inject) and store at -20° C before use. Use each vial once then discard it. Before use, allow the ampoule to come to room temperature (maximum 25 °C) in the dark without heating. Cut the ampoule with a glass knife and using a Pasteur pipette, rapidly transfer the content of the ampoule into a 50 mL pre-tarred volumetric flask, weigh and make up to the mark with n-hexane. Dilute accordingly to the type of injector used. NOTE This solution keeps for about six months if stored in the dark at -20° C. To prevent contamination of the standard solution, immediately distribute the solution into different vials (ready to inject) and store at -20° C before use. Use each vial once then discard it. 5.19.4 Diluted calibration standard solution 5.20 Commercially available calibration standard FAME mixture solution

6 Apparatus

WARNING — Since the determination involves the use of volatile flammable solvents, all electrical apparatus employed shall comply with legislation relating to the hazards in using such solvents.

Usual laboratory equipment and, in particular, the following.

6.1 Analytical balance , capable of weighing to the nearest 1 mg, with a readability of 0,1 mg.

6.2 One-mark volumetric flasks , capacities 50, 100, 250, 300 and 500 ml.

6.3 One mark volumetric pipettes, 2, 5, 10, 25 and 50 ml, ISO class AS (ISO).

6.4 Two-marks Pipette, volumetric, with two marks, capacities 2 and 5 ml, class AS (ISO).

6.5 Micropipette, capacity 200 µl.

6.6 Dispensers, capacities 2, 5 and 10 ml.

6.7 Test tube, of diameter 26 mm, of length 100 mm, fitted with PTFE-lined screw cap.

6.8 Test tube Mixer Vortex Genie.

6.9 Laboratory centrifuge , equipped with adapters for test tubes with external diameter of 26 mm.

5

© ISO 2013 – All rights reserved