Standardised analytical procedures

For reproducible analyses and reliable control of polycyclic aromatic hydrocarbons (PAH) and related heterocyclic compounds, the availability of standardised analytical procedures is essential. When national or international regulations are issued or developed, standardised analytical methods are usually mandatory. 

Standardisation Norms, validated analytical procedures, certification... 

Two synthetic internal standards are used (nor-DCA and nor-CA) to perform an external standardisation method. Calibration curves for each compound are built, starting from known amounts of standards ranging from 0.02 pg to 0.2 pg. BA standards are prepared and analysed as described in below in section 5.4.5.3 Analytical, Procedure . 

Analytical measurements should be made with properly tested and documented procedures. These procedures should utilise controls and calibration steps to minimise random and systematic errors. There are basically two types of controls (a) those used to determine whether or not an analytical procedure is in statistical control, and (b) those used to determine whether or not an analyte of interest is present in a studied population but not in a similar control population. The purpose of calibration is to minimise bias in the measurement process. Calibration or standardisation critically depends upon the quality of the chemicals in the standard solutions and the care exercised in their preparation. Another important factor is the stability of these standards once they are prepared. Calibration check standards should be freshly prepared frequently, depending on their stability (Keith, 1991). No data should be reported beyond the range of calibration of the methodology. Appropriate quality control samples and experiments must be included to verify that interferences are not present with the analytes of interest, or, if they are, that they be removed or accommodated. 

Analytical procedures involve analysing the job against key factors and competencies and then scoring these using a standardised points system. An example of such a sys-... 

Chemical analysis always involves the use of different chemicals. In order to assure accurate analysis results, the chemicals used need to he standardised, the procedures must he followed exactly and the data obtained have to he analysed statistically. If an instrument is used, it should be maintained and calibrated properly. A detailed description of analytical chemistry is not the purpose of this book. Readers can refer to analytical chemistry books in the literature. During the last five decades, sophisticated instruments in the market have made chemical analysis much easier than before. However, the price of the instruments plus high operation costs have limited their applications in many textile businesses. Therefore, the analytical methods discussed in this chapter are mainly those of traditional wet chemistry based analyses. 

It is only in 1958, when Stahl standardised the procedure and showed its wide applications, that thin layer chromatography (a derivative of paper chromatography) became a technique that is now used extensively and has become a "classic" Gas chromatography (GC) was first described in 1952 by Martin and James and, by the 1960 s, became the most sophisticated and used analytical technique for mixtures of gases and for volatile liquids and solids. This naturally led to its counterpart hquid chromatography or high-performance Liquid Chromatography (HPLC) preferred technique for separation of non-volatile or thermally unstable species. 

Reliable data on groundwater quality are essential to guide policy for sustainable resource management and effective resource protection. Whilst appropriate and standardised analytical and sampling procedures are required for this purpose, they on their own are not enough, since it is even more critical that the groundwater samples collected are ... 

In order to permit the consistent assessment of the health effects of environmental pollutants with wide ranging distributions, and to ensure reliable analytical control,the harmonisation or standardisation of sampling and analytical procedures is desirable. Where national or international regulations are in force or being developed, the availability of accepted standard methods is usually mandatory. 

To ensure full comparability of results, all the various steps which are involved in the analytical procedures (sampling, sample extraction, enrichment, clean-up, analytical method and data presentation) should be considered in harmonisation and standardisation discussions. 

In clinical investigations, the use of SIM for isotope dilution studies provide an accurate reference method for a specific assay against which routine laboratory analytical procedures may be standardised [82]. A comprehensive review of SIM has appeared recently [83]. 

Several sample pre-treatment methods have been proposed, aiming both at sample clean-up to reduce interferences and pre-concentration of which some have been duly validated and integrated in standardised analysis procedures and automated devices (Pinheiro et al. 2004). Those pre-treatments will increase the accuracy and sensitivity of the detection and lead to faster analyses and better reproducibility. Besides, these procedures may attain minimal sample volume requirements and avoid of analyte losses through evaporation. Liquid-phase extraction, LPE, (Alaejos et al. 2008 Sun et al. 2012b) solid-phase extraction, SPE, (Alaejos et al. 2008 Martinez et al. 2000), solid-phase microextraction, SPME, (Alaejos et al. 2008 DeBruin et al. 1999 Sharma et al. 2011), liquid-liquid-liquid microextraction. 

Procedure. Prepare a manganese(II) sulphate solution (approx. 0.05M) by dissolving 11.15 g of the analytical-grade solid in 1 L of de-ionised water standardise the solution by titration with 0.05 M EDTA solution using solochrome black indicator after the addition of 0.25 g of hydroxylammonium chloride — see below. 

Method A With arsenic(III) oxide. This procedure, which utilises arsenic(III) oxide as a primary standard and potassium iodide or potassium iodate as a catalyst for the reaction, is convenient in practice and is a trustworthy method for the standardisation of permanganate solutions. Analytical grade arsenic(III) oxide has a purity of at least 99.8 per cent, and the results by this method agree to within 1 part in 3000 with the sodium oxalate procedure (Method B, below). 

Selected references. These procedures were adapted essentially from AO AC Official Methods of Analysis [7s], The Society for Analytical Chemistry, Official, Standardised and Recommended Methods of Analysis [8g], UK Ministry of Agriculture Technical Bulletin 27 [21], Subcommittee on Procedures of the Chemistry Task Force of the (US) National Shellfish Sanitation Program [24] and Joint FAO/WHO Food Standards Programme, Codex Alimentarius Commission [125b]. Other pertinent references are 30i, 37a, 38d, 39d and 128b. 

Selected references to Section III these procedures were adapted from The Society for Analytical Chemistry, Official, Standardised and Recommended Methods of Analysis [8h] and Gorsuch [139]. 

Atomic absorption analysis made available to the routine laboratory an analytical technique which initially was intended to produce considerable simplification of procedures for the analysis of aqueous, acidic or basic solutions, and thereby contribute to a reduction in costs. Numerous reviews show the worldwide application of this technique [15, 40, 77, 126—129, 137]. Nevertheless, some 10 years passed before atomic absorption became part of the international standardisation of analytical methods. At present, there are many standard methods being developed on the basis of atomic absorption [35, 67], Some, dealing with the determination of metals in lubricating oils, are already in use [35, 66], although the overwhelming majority, for example those dealing with the analysis of iron ores [67], are still being developed. The first indication of standardisation of atomic absorption methods for iron and steel analysis was seen in 1973 [8]. 

In accordance with Article 7a of the WHG, the AbwV (Ordinance on Requirements for the Discharge of Wastewater into Waters - Wastewater Ordinance) has been divided into a general framework section, an annex (to Article 4) with analytical methods for parameter determination and sector-specific appendices, including requirements for 53 wastewater sectors [3], Minimum requirements to be stipulated when granting a permit to discharge wastewater are described, analysis and measurement techniques are specified in the annex and sector-specific requirements in the appendices refer to the analysis and measurement techniques specified in the annex. Article 4 of the AbwV, in conjunction with the annex, lists the analysis and measurement procedures that are to be used to determine the parameters defined in the appendices. Paragraph 2 emphasises that for individual cases other equivalent procedures may be required if compliance with the requirements specified in the ordinance is to be ensured [9]. All analysis and determination procedures are standardised methods (DIN, CEN, ISO). 

According to the procedure proposed. Member States were extensively consulted during 2006 for revision of CEN biologic standard methods (Table 1.3.6) for their relevance in the context of the WFD and to identify priority areas for future standardisation activities. It became apparent from this process that sampling and quality assurance methods are mostly needed at community level, and also that published standard methods often do not take into account water category type-specific features, as is required in the Directive. This consultation process enabled the identification of a number of candidate sampling and analytical methods fulfilling short-tenn standardisation needs for lakes, rivers and coastal waters. 

Over the last few years, the measurement methodology of the nutritional value of feedstuffs has been the topic of concerted studies at the European level, with particular emphasis on the standardisation of in vivo methods (Perez et o/., 1995a) and on the harmonisation of analytical methods for feeds and faeces (EGRAN, 2001). This resulted in the adoption of a European reference method to determine the digestibility of diets (Perez et al., 1995b) and in the harmonisation of the procedures used to calculate the nutritional value of feed materials within mixtures of feedstuffs (Villamide et al., 2001). 

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