1、BRITISH STANDARD BS3762-3.5: 1986 Analysis of formulated detergents Part3: Quantitative test methods Section3.5 Methods for determination of total organic matter content NOTEIt is recommended that this Section be read in conjunction with the information in the “General Introduction”, published separ
2、ately as BS3762-0. UDC 661.185:543BS3762-3.5:1986 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 30 September1986 BSI11-1999 The committees responsible for this British
3、Standard are shown inPart0. The following BSI references relate to the work on this standard: Committee reference CIC/34 Draft for comment85/52540 DC ISBN 0 580 15325 8 Foreword This Section of BS3762 has been prepared under the direction of the Chemicals Standards Committee and supersedes method B1
4、 of BS3762:1964, which has been deleted by amendment. This standard describes a method of test only and should not be referred to as a specification defining limits of purity. Reference to the standard should indicate that the method of test used is in conformity with BS3762-3.5. A British Standard
5、does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an i
6、nside front cover, pagesi andii, pages1 and2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Dat
7、e of issue CommentsBS3762-3.5:1986 BSI 11-1999 i Contents Page Foreword Inside front cover 1 Scope 1 2 Principle 1 3 Reagents 1 4 Apparatus 1 5 Procedure 1 6 Expression of results 2 7 Precision 2 8 Test report 2 Publications referred to Inside back coverii blankBS3762-3.5:1986 BSI 11-1999 1 1 Scope
8、This Section of BS3762 describes methods for separating organic constituents from most of the inorganic constituents, and for determining the total organic matter content of formulated detergents. Two procedures are described. Method1 is widely applicable and is intended mainly for solid samples. Me
9、thod2 is restricted to samples containing less than10% alcohol-insoluble matter and is intended mainly for liquids. Small but significant amounts of alkali metal carbonates, hydroxides and chlorides may accompany the organic matter, and organic compounds that are volatile, e.g.perfumes and unsulphon
10、ated alkylates, or that are sparingly soluble in ethanol, will not be completely determined. Consequently, the gravimetric part of the method is applicable only when the proportions of these classes of compounds are negligible or when an approximate indication of the total organic matter content is
11、adequate. NOTEThe titles of the publications referred to in this Section are listed on the inside back cover. 2 Principle Extraction with hot ethanol, filtration and, if a quantitative result is required, evaporation of an aliquot portion of the filtrate and weighing the residue. 3 Reagents The reag
12、ents shall be of a recognized analytical reagent grade. 3.1 Ethanol NOTEFor the purposes of3.1, the ethanol may be replaced by industrial methylated spirits complying with BS3591, of such spirits diluted as required. It should be noted that the use of industrial methylated spirits is governed by The
13、 Methylated Spirits Regulations,1983 (S.I.1983 No.252). It is not permissible to use duty-free ethanol, received under the provisions of the Alcoholic Liquors Duties Act1972, Section10, for purposes for which industrial methylated spirits is an acceptable alternative. 3.2 Acetone 4 Apparatus Ordinar
14、y laboratory apparatus and the following are required. 4.1 One-mark volumetric flask,250mL, complying with BS1792. 5 Procedure 5.1 Method1 5.1.1 Test portion. Weigh, to the nearest0.01g, about10g of the laboratory sample into a600mL beaker. 5.1.2 Extraction of organic matter. Add approximately250mL
15、of the ethanol(3.1) to the test portion. Cover with a watch glass, heat and stir with a mechanical or magnetic stirrer until the ethanol is boiling. Continue boiling and stirring for5min. Allow the beaker and contents to cool to about60 C and the insoluble matter to settle. Filter the ethanolic phas
16、e through a medium grade filter paper. Repeat this extraction twice more with new250mL portions of ethanol. Add approximately75mL of the ethanol at50 C to60 C to the beaker containing the insoluble matter; break any remaining hard lumps with a glass rod. Allow the insoluble matter to settle and filt
17、er through the same filter paper. Repeat this operation twice more. Evaporate the combined filtrate and washings to less than250mL. Transfer to the250mL one-mark volumetric flask(4.1), cool and dilute to the mark with ethanol. NOTEA portion of the ethanol soluble fraction may be used for the determi
18、nation of total non-ionic matter content (see BS3762-3.7). 5.1.3 Determination. Shake to disperse any precipitate, and pipette100mL of the alcoholic solution into a tared250mL beaker. Evaporate on a steam bath in a fume cupboard. Inspect occasionally and guard against loss of sample by excessive foa
19、ming or bumping. Add10mL of the acetone(3.2), and evaporate to dryness. Inspect occasionally and guard against loss of sample by excessive foaming or bumping. Allow to cool in a desiccator and weigh. Repeat the operations of the previous paragraph until successive weighings agree to within0.003g. 5.
20、2 Method2 5.2.1 Test portion. Weigh, to the nearest0.001g, about4g of the laboratory sample into a600mL beaker. 5.2.2 Extraction of organic matter. Add about100mL of the ethanol(3.1) to the beaker. Cover with a watch glass and commence stirring and heating on a steam bath in a fume cupboard until th
21、e alcohol is boiling. Continue boiling for5min. Allow to cool to about60 C and filter through a medium fast filter paper (fine grade for liquid scourers) into the250mL one-mark volumetric flask(4.1).BS3762-3.5:1986 2 BSI 11-1999 Wash the beaker and residue in the filter paper with about50mL of hot e
22、thanol. Repeat once. Allow to cool. Dilute to the mark with cold ethanol and mix. 5.2.3 Determination. Proceed in accordance with5.1.3. 6 Expression of results The organic matter content, expressed as a percentage by mass, is given by the following expression: where m 1is the mass of residue (in g);
23、 m 2is the mass of sample taken (in g). NOTEThe results should be interpreted with caution according to the requirements of the determination (see clause1). 7 Precision The precision is expected to depend markedly upon the content and the nature of the organic matter. Some typical values are given b
24、elow. The precision data were determined from an experiment conducted in1985 involving seven laboratories. NOTEFor the meaning of the precision terms see BS5497-1. 8 Test report The test report shall include the following information: a) a reference to this British Standard, i.e.BS3762-3.5:1986; b)
25、a reference to the test method used, i.e.method1 or method2; c) the results expressed in accordance with clause6; d) a complete identification of the sample. Mean result Repeatability Reproducibility Detergent powder (Method1) % 14 % 1.0 % 2.2 Dishwashing liquid (Method2) 42 1.2 3.8 m 1 250 100 - 10
26、0 m 2 - m 1 250 m 2 - =BS3762-3.5:1986 BSI 11-1999 Publications referred to BS1792, Specification for one-mark volumetric flasks. BS3591, Specification for industrial methylated spirits. BS3762, Analysis of formulated detergents. BS3762-3.7, Method for determination of total non-ionic matter content
27、. BS5497, Precision of test methods. BS5497-1, Guide for the determination of repeatability and reproducibility for a standard test method. BS3762-3.5: 1986 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishS
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