BS ISO 14382:2012 pdf download – Workplace atmospheres — Determination of toluene diisocyanate vapours using 1-(2-pyridyl) piperazine- coated glass fibre filters and analysis by high performance liquid chromatography with ultraviolet and fluorescence detectors

BS ISO 14382:2012 pdf download – Workplace atmospheres — Determination of toluene diisocyanate vapours using 1-(2-pyridyl) piperazine- coated glass fibre filters and analysis by high performance liquid chromatography with ultraviolet and fluorescence detectors All dilutions of the stock solutions are made to arrive at the working range in 90 + 10 parts by volume ACN + DMSO. For example, a stock standard prepared in DMSO can be diluted 1→10 with pure ACN to arrive at 90 + 10 parts by volume ACN + DMSO. Any further dilutions are made with 90 + 10 parts by volume ACN + DMSO. 5.2.2 Preparation of analytical standards using pure TDI Analytical standard solutions can also be prepared by reacting TDI (either pure 2,4-TDI or pure 2,6-TDI isomer) with 1-2PP in solution. Prepare a solution containing 1 mg/ml (0,006 mmol/l) 1-2PP by diluting 100 mg of 1-2PP to the mark with 90 + 10 parts by volume ACN + DMSO in a 100 ml volumetric flask, ISO 1042, [1] class A. Prepare a separate solution of 1 mg/ml (0,006 mmol/l) pure TDI by carefully and accurately weighing 50 mg of TDI (to three significant figures) and diluting it to the mark with 90 + 10 parts by volume ACN + DMSO in a 50 ml volumetric flask. Pipette 1 ml to 3 ml of the 1 mg/ml TDI solution into a 25 ml volumetric flask and dilute to the mark with the 1 mg/ml 1-2PP solution. Mix the solution well and allow it to react overnight. Do not use more than 3 ml of the TDI solution in order to ensure a proper excess of 1-2PP. Do not use the conversion factor in 5.2.1 to calculate the concentration of these standards. Use fresh solutions. The amount of pure TDI isomer shall be accurately known to prepare accurate standards. 5.2.3 Commercial standard solutions Analytical standard solutions are commercially available. 5.3 Filter extraction solution This solution is composed of 90 + 10 parts by volume ACN + DMSO. 5.4 1-2PP filter coating solution This solution is composed of 4 mg/ml (0,025 mmol/l) 1-2PP in methylene chloride. 5.5 HPLC mobile phase This solution is composed of 0,01 M ammonium acetate (buffered to pH 6,2 with acetic acid) in water and acetonitrile. The exact composition of the mobile phase depends on the HPLC column selected for use. The buffered ammonium acetate solution can be prepared separately and used...