Standardised methods of analysis

There are several publications detailing standard or officially recognized methods of fertilizer analysis. These include Official Methods of Analysis of AOAC International (Horwitz, 2000) Official and Standardised Methods of Analysis, published by the Royal Society of Chemistry (Watson, 1994) and Fertilisers - Methods of Analysis used in OEEC Countries (OEEC, 1952). There are also the EEC methods, which have been implemented in the UK by the Fertilisers (Sampling and Analysis) Regulations 1996 (Statutory Instrument (SI) 1996 No. 1342). The title page of the SI may be downloaded from the following website ... 

The Analytical Methods Committee s own compilation of official and standardised methods of analysis is widely used and respected within the analytical community. The importance of standardised formats for method documentation has been emphasised by the AMC s guidelines for achieving quality in trace analysis. They list 17 headings for inclusion in the documentation ... 

C.A. Watson, ed.. Official and Standardised Methods of Analysis, Royal Society of Chemistry, Cambridge, 3rd edn., 1994. 

The suitability of this method to determine compliance with the legislation has been discussed within CEN/TC194/SC1 where it was suggested that the colorimetric method should be used only for screening purposes and that PAA levels above 2 pg/kg (as aniline) should be verified using a specific method. As a result a standardised method of analysis is required to determine the migration of individual PAAs from food contact materials and articles, to ensure compliance with the legislation. 

HPLC-QFAAS is also problematical. Most development of atomic plasma emission in HPLC detection has been with the ICP and to some extent the DCP, in contrast with the dominance of the microwave-induced plasmas as element-selective GC detectors. An integrated GC-MIP system has been introduced commercially. Significant polymer/additive analysis applications are not abundant for GC and SFC hyphenations. Wider adoption of plasma spectral chromatographic detection for trace analysis and elemental speciation will depend on the introduction of standardised commercial instrumentation to permit interlaboratory comparison of data and the development of standard methods of analysis which can be widely used. 

The development of methods of analysis for incorporation into International Standards or into foodstuff legislation was, until comparatively recently, not systematic. However, the EU and Codex have requirements regarding methods of analysis and these are outlined below. They are followed by other International Standardising Organisations (e.g. AOAC International (AOACI) and the European Committee for Standardization (CEN)). 

Hanson, N. W., Official Standardised and Recommended Methods of Analysis, SAC, London, 1973. 

In 1935, the Committee was renamed the Analytical Methods Committee (AMC) but the main analytical work was carried out by sub-committees composed of analysts with specialised knowledge of the particular application area. The earliest topics selected for study were milk products, essential oils, soap and the determination of metals in food colourants. Later applications included the determination of fluorine, crude fibre, total solids in tomato products, trade effluents and trace elements, and vitamins in animal feeding stuffs. These later topics led to the publication of standard methods in a separate booklet. All standard and recommended methods were collated and published in a volume entitled Bibliography of Standard, Tentative and Recommended or Recognised Methods of Analysis in 1951. This bibliography was expanded to include full details of the method under the title Official, Standardised and Recommended Methods of Analysis in 1976 with a second edition in 1983 and a third edition in 1994. 

The development, revision and promulgation of validated, standardised and official methods of analysis. 

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. 

Methods of analysis Preferably optional to the laboratories, regulations on validation Preferably method standardisation, additional regulations on validation (going further than DG III)... 

Article 8, paragraph 3 of the WFD requires that technical specifications and standardised methods for analysis and monitoring of water status be laid down in accordance with the procedure given in Article 21. Moreover, Annex V. 1.3.6 of the WFD states that the standards for monitoring of quality elements for physico-chemical parameters shall be any relevant CEN/ISO standards or such other national or international standards, which will ensure the provision of data of an equivalent scientific quality and comparability. 

Class reactions for many of the compounds are either few or non-existent and thus an evaluation of recoveries or reproducibility of the analyses is difficult. A review of the literature concerning natural lipids in seawater high-l hts the fact that detailed information has been gathered at the expense of any wide aerial surveys of the levels of these compounds in ocean waters. The concentration ranges found by various workers vary widely and in the absence of standardised methods of extraction and analysis, intercomparison of results is often impossible. 

Traditionally, standardised methods are based on techniques which are widely available and easy to handle for routine applications, which usually excludes advanced techniques requiring expensive equipment or special experience. In addition, standardised or recommended methods of analysis are often supported by the development of reference materials and related data for calibration and intercomparison purposes. 

As many oils, other than those included in the official publications, are met with in pharmaceutical practice, the most useful chemical methods of analysis are given briefly below. The Analytical Methods Committee of the S,A,C, (referred to below as the S,A,C,) has carried out a considerable amount of useful work on standardisation of methods for the analysis of essential oils, and many of its recommendations have been embodied in the official monographs. 

A useful method of analysis is to dissolve a known mass of the compound in a known excess of standardised ascorbic acid solution, back-titrating the excess with standardised Mn(III) sulphate solution or other oxidants. Alternatively, a known mass of the compound is treated with an excess of iodide solution, titrating the liberated iodine with standardised thiosulphate. 

An external standardisation method is employed to perform quantitative analysis. In the cited study, calibration curves for each compound are obtained by injecting amounts ranging from 0.08 to 10 nmol. The amount of injected standards is logarithmically proportional to the peak area. 

The widespread use of chromatography in quantitative analysis is mainly due to its reliability and to its use in standardised analyses. This type of analysis relies mainly on reproducibility of the separation and on the linear relationship that exists between the injected mass of the compound and the area of the peak in the chromatogram. The use of an integrating recorder or a microcomputer with the appropriate data treatment software allows automation of all the calculations associated with the analysis. Computer software can analyse the results and produce a computerised report. Trace and ultratrace analyses by chromatography are often the only recognised methods (EPA Methods for Environmental Analyses), although their costs are relatively high. The three most widely used methods are described below in their simplest formats. 

Quantitative Analysis of Mixtures of Sugars by the Method of Partition Chromatography. Part 1. Standardisation of Procedure, A. E. Flood, E. L. Hirst, and J. K. N. Jones,/. 

Both variolin B and its 5-deoxy derivative 19 (Scheme 6.1 Part 2) have shown promise in pharmacokinetic and in vivo studies. These compounds have been shown to have long terminal half-lives and low normal cell toxicity, however the 5-deoxy derivative demonstrated better Cmax, plasma clearance and terminal plasma half-life.318,319 Both are effective against human lung carcinoma cell lines in nude mice.104 The deoxy-variolin B showed growth inhibitory activity against human leukemic cell lines.105 A standardised method for liquid chromatography-mass spectrometry (LC-MS)/MS analysis of plasma has been developed to monitor the results of the in vivo studies.320... 

Methods for the calculation of pressure drop through pipes and fittings are given in Section 5.4.2 and Volume 1, Chapter 3. It is important that a proper analysis is made of the system and the use of a calculation form (work sheet) to standardise pump-head calculations is recommended. A standard calculation form ensures that a systematic method of calculation is used, and provides a check list to ensure that all the usual factors have been considered. It is also a permanent record of the calculation. Example 5.8 has been set out to illustrate the use of a typical calculation form. The calculation should include a check on the net positive suction head (NPSH) available see section 5.4.3. 

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). 

All analysis and measurement procedures cited in the AbwV and AbwAG are standardised methods, either by DIN, ISO or CEN. Development and standardisation of biotests for emission control are carried out by national working groups on biotests (DIN), resulting in DIN standard protocols since 1976. Representatives of federal government, the Lander, industry and universities are usually present in the national working groups. 

---