British Standards sampling procedures

British Standards Institution (1971) Sampling Procedures, London. 

The British Standard method (331) of test for spices and condiments gives a procedure for the determination of total capsaicinoid content of chilies and chili oleoresins by HPLC. The powdered or ground sample is mixed with an equal volume of acid-washed sand and Soxhlet extracted for 6-8 h with MeOH. The filtered extract, diluted with MeOH, is analyzed by HPLC on a Cl8 column, with an ACN-HzO-glacial acetic acid mobile phase and detection at 280 nm. Oleoresins are diluted with MeOH and analyzed in a similar manner. 

Agency, 2006). The scheme provides a framework within which environmental measurements can be made in accordance with the Agency s quality requirements and this includes documentation of the sampling and analytical procedures. Internationally, laboratories use the ISO/IEC 17025 Standard (British Standards, 2005) to implement a quality system aimed at improving their ability to produce valid results consistently. As the Standard is about competence, accreditation is simply formal recognition of a demonstration of that competence. 

Although it is common practice to calibrate the Coulter Counter using a standard powder, it is possible to calibrate the instrument with the powder being examined. This is the preferred British Standard method [17]. It is reiterated that this procedure cannot be carried out with some instruments due to count loss. Essentially one balances the volume of particles passing through the measuring aperture with the known volume in the measurement sample. This serves a multiple purpose in that ... 

Because most limestone is used locally, many countries have their own standards for sampling, sample preparation and testing. This chapter refers mainly to European (CEN) and British Standards, to illustrate the principles and procedures involved. Where appropriate, the reader should adopt the requirements of the relevant national or international standards. 

British suspended particulate sampler In recent years the old British standard method has been super-ceded by European directives such as EN12341 Air Quality - Field test procedure to demonstrate reference equivalence of sampling methods for the PMIO fraction of particulate matter. The determination of smaller size fractions (PM2.5) is also covered by a further directive. The US EPA have similar standard reference methods for particulate material (USEPA 40 CFR part 50). An early method was to simply compare the color of a filter paper through which a volume of air was drawn to an incremental gray scale (16 shades from white to black) this was then converted into an integrated particle loading with reference to the size cut-off offered by the pore size of the filter used. This was known as the black smoke index method. 

An alternative strategy is appropriate if determinations are to comply with a standard scheme of analysis, such as those developed by the British Standards Institution for the analysis of ceramic and refractory materials. In these schemes, samples are prepared as fused glass disks and calibration samples may then be prepared in the same way using specified proportions of high-purity element oxides. This calibration procedure can, therefore, be considered to be absolute in contrast to the relative measurements made against reference samples. 

The BP Commission can also call on expertise available in the British Pharmacopoeia laboratories situated in the premises of the Laboratory of the Government Chemist in West London. The BP laboratory carries out and validates assay procedures for the Commission and in addition, is responsible for the procurement, establishment, maintenance and sale of British Pharmacopoeia Chemical Reference Substances (BPCRS). These reference substances, as their name suggests, are authentic samples of a drug or decomposition product which are used as standards in a drug assay. The BP laboratory also fulfils an important forensic role in the control of counterfeit medicines. With the advent of the internet, the public can easily gain access to supplies of prescription-only medicines online. These medicines are often adulterated, contaminated or simply counterfeit, and comparison with authentic samples is necessary to ensure that the correct preparation is supplied. 

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