BS 6069-3.4 specifies a charcoal tube/gas chromatographic method for the determination of the concentration of vaporous aromatic hydrocarbons in workplace air.
The method described in BS 6069-3.4 is valid for concentrations of airborne vapours of these compounds in the range from approximately 1 mg/m3 to 1 000 mg/m3 (about 0,2 ml/m3 to 200 ml/m3; see 8.1) when sampling 10 litres of air.
BS 6069-3.4 cannot be used to measure instantaneous or short-term fluctuations in concentrations. Alternative on-site procedures, such as gas chromatography or infrared spectrometry.
The method described in BS 6069-3.4 is also valid for the measurement of airborne concentrations of mixtures of these compounds. In such cases, the unique properties of each compound have to be considered when determining the volume of air to be sampled and the gas chromatographic conditions to be used.
NOTE 1 The upper limit of the useful range is set by the adsorptive capacity of the first section of the charcoal tube (5.1) used. This capacity is measured as a break-through volume of air, which should not be exceeded during sampling (see clause 6 and Annex A).
NOTE 2 When analyzing aromatic hydrocarbon mixtures with very large differences in concentrations and in which several compounds are present, the reproducibility and repeatability of the compounds of minor importance might be influenced.
BS 6069-3.4 on ambient air is relevant to:
Organic components which have the same or nearly the same retention time as the substance analyzed during the gas chromatographic analysis will interfere. Interferences can be minimized by proper selection of gas chromatographic columns and programme conditions.
BS 6069-3.4 specifies requirements and test methods for the determination of vaporous aromatic hydrocarbons by charcoal tube/solvent desorption/gas chromatography.
BS 6069-3.4 describes the performance characteristics and sets the relevant minimum criteria required for determining the aromatic hydrocarbons in gases and vapour.
In BS 6069-3.4, performance criteria and test procedures for measuring air quality are provided to test and manufacture air quality measuring diffusers. This helps create an improved solution to deal with harmful gasses emitted by stationary sources, which are very toxic.
As a whole, BS 6069-3.4 is a best practice guidance standard that provides complete requirements and test procedures for determining the hydrocarbons of vapor and gases using different methods and controlling their quality, which will reduce pollution, increase efficiency, and ease health concerns.