BS 15853:2010 pdf download – Ambient air quality — Standard method for the determination of mercury deposition 6.9 Bromine monochloride (BrCl) solution, 0,5 % V/V for cleaning purposes, prepared of Bromine monochloride (BrCl) solution (6.8) by dilution with ultrapure water (6.3). 6.10 Hydroxylammonium hydrochloride solution. Dissolve 12,0 g NH 2 OH·HCl in 100 ml water (6.3). This chemical reagent sometimes contains high mercury concentrations. Adding 0,1 g Chelex 100 ion exchange material can lower the mercury content. Blanks shall be checked carefully. NOTE Instead of hydroxylammonium hydrochloride solution ascorbic acid can be used. Ascorbic acid solution can be prepared weekly by dissolving 10 g of L-ascorbic acid in 100 ml water (6.3). 7 Sampling 7.1 Sampling equipment – General requirements Use collectors with a defined horizontal opening, either a funnel/bottle combination (see A.1 and A.3) or a wide-mouthed jar (see A.2). The collectors can be bulk samplers, which collect at all times, or wet-only samplers which collect only during wet precipitation events. If a funnel/bottle collector is used, the funnel shall have a cylindrical vertical section of sufficient height to avoid sampling losses resulting from splashing. If a jar is used, it shall have a sufficient depth to avoid such sampling losses. Collector dimensions shall be selected with respect to the expected precipitation collected in the sampling period used. Typical sampling periods vary between one week and one month. The funnel area shall be large enough to provide sufficient sample for chemical analysis at a minimum precipitation depth of 1 mm per week. It is recommended that short sampling periods (weekly) and/or two or three samplers in parallel are used. The sampling efficiency of funnel/bottle collectors can be checked by comparing the collected precipitation with the precipitation determined using a standard meteorological rain gauge. The difference in precipitation between the standard rain gauge and the heavy metal sample collector shall not be greater than 20 % for precipitation depths between 1 mm to 2,5 mm, and not greater than 10 % for precipitation depths larger than 2,5 mm of precipitation [9]. Checking sampling efficiency is especially important if a wet-only collector is used. Mercury deposition is collected in special precipitation samplers, which are used only for mercury deposition determinations. All parts of the precipitation collector that are in contact with the sample shall consist of materials that do not alter the mercury content of the sample (e.g. glass, fluorocarbon polymers)....
Download Address
Download