ISO 17735:2019 pdf free

ISO 17735:2019 pdf free.Workplace atmospheres – Determination of total isocyanate groups in air using 1-(9-anthracenylmethy) piperazine (MAP) reagent and liquid chromatography
A measured volume of air is drawn through either an impinger containing a solution of 1-(9-anthracenylmethy)piperazine (MAP), a filter impregnated with MAP, or a sampling train consisting of an impinger followed by an impregnated filter. The choice of sampler depends on the chemical and physical characteristics of the airborne isocyanate[14]. If an impinger is used, the solution is subjected to solid-phase extraction (SPE) and the eluate is concentrated and analysed by reverse phase high performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance and fluorescence (FL) detection in series. If an impregnated filter is used for sampling, it is extracted with solvent either in the field after completion of sampling or in the laboratory. Waiting to extract the filter until after the sample has been received by the analytical laboratory is acceptable only for analysis of isocyanates collected as vapour. This solution is filtered and analysed by HPLC/UV/FL.
Isocyanate-derived peaks are identified based on their UV and FL responses and by comparison with the chromatogram of a derivatized bulk isocyanate product if available. Quantification of compounds for which analytical standards are available (generally monomers) is achieved by comparison of the FL peak height of the sample peak with the FL peak height of standard matching solutions. Quantification of compounds for which analytical standards are not available is achieved by comparison of the UV area of the sample peak with the UV area of the appropriate monomer standard (i.e. the monomer from which the isocyanate product is derived).
Structures of some common disocyanate monomers are shown in Figure 1.
While stirring this solution, add the 9-( chloromethyl)anthracene solution dropwise over a 30 min period. Rinse down the dropping funnel with an additional 10 ml of dichloromethane. Allow the reaction to continue while stirring for at least 2 h.
Using a separating funnel, wash the reaction mixture three times with 130 ml water by shaking vigorously for 1 min. Discard the emulsion that forms after the first wash, which contains primarily an impurity and not MAP. Discard the aqueous washings.ISO 17735 pdf free download.