1、BRITISH STANDARD BS 3762-1: 1983 ISO607:1980 Analysis of formulated detergents Part 1: Methods of sample division ISO title: Surface active agents and detergentsMethods of sample division NOTEIt is recommended that this Part be read in conjunction with the information in the “Generalintroduction”, p
2、ublished separately as BS3762-0. UDC 661.185:543.05BS3762-1:1983 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffect on 30December1983 BSI 12-1999 The committees responsible for
3、this British Standard are shown inPart0. The following BSI references relate to the work on this standard: Committee reference CIC/34 Draft for comment78/56082 DC ISBN 0 580 13557 8 National foreword This Part of BS3762 has been prepared under the direction of the Chemicals Standards Committee. It i
4、s identical with ISO607:1980 “Surface active agents and detergentsMethods of sample division”, published by the International Organization for Standardization (ISO). This Part supersedes part1 of BS3762:1964 (which effected division of solid samples using either a radial sampling tool or a multiple
5、slot divider) by methods using a conical or a rotary sample divider and gives, additionally, methods for the division of samples in paste or in liquid form. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without
6、 deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Part of this British Standard”. Cross-r
7、eference. The Technical Committee has reviewed the provisions of ISO6206, to which reference is made in clause3, and has decided that they are suitable for use in conjunction with this standard. A related British Standard to ISO6206 is BS5309 “Methods for sampling chemical products”, Part1 “Introduc
8、tion and general principles”. A British Standard 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
9、pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to6, 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.
10、Amendments issued since publication Amd. No. Date of issue CommentsBS3762-1:1983 BSI 12-1999 i Contents Page National foreword Inside front cover 1 Scope and field of application 1 2 Reference 1 3 Definitions 1 4 Principle 1 5 Procedure 1 6 Storage of the reduced sample 3 7 Report 3 Figure 1 Explode
11、d view of a typical conical divider 4 Figure 2 Diagram of a typical conical divider 5 Figure 3 Perspective view of a typical rotary sample divider 6 Publication referred to Inside back coverii blankBS3762-1:1983 BSI 12-1999 1 1 Scope and field of application This International Standard specifies met
12、hods for obtaining a reduced sample of surface active agent or detergent suitable for use with single or mixed products, in the form of powders, pastes or liquids. The sample reduction process may be required for the following reasons: a) the preparation of a final sample or a laboratory sample of m
13、ass greater than250g from a blended bulk sample of mass greater than500g; b) the preparation of several equivalent laboratory samples and/or reference samples and/or storage samples, each of mass greater than250g, from a final sample; c) the preparation of a test sample from a laboratory sample. 2 R
14、eference ISO6206, Chemical products for industrial useSamplingVocabulary. 3 Definitions 1) 3.1 bulk sample a collected set of samples which do not maintain their individual identities 3.2 blended bulk sample a collected set of samples blended together to obtain a uniform bulk sample 3.3 reduced samp
15、le a sample that has been obtained by reducing the quantity of another sample without change of composition NOTEIt may also be necessary to reduce the particle size in the course of reducing the quantity. 3.4 final sample a sample obtained or prepared under the sampling plan for possible subdivision
16、 into identical portions for testing, reference or storage 3.5 laboratory sample a sample as prepared for sending to the laboratory and intended for inspection or testing 3.6 reference sample a sample prepared at the same time as, and equivalent to, the laboratory sample, which is acceptable to the
17、parties concerned, and retained for use as a laboratory sample if a disagreement occurs 3.7 storage sample a sample prepared at the same time as, and equivalent to the laboratory sample, and intended for possible future use as a laboratory sample 3.8 test sample a sample prepared from the laboratory
18、 sample and from which test portions will be taken 4 Principle Reduction of a bulk sample by a mechanical process until a reduced sample is obtained. 5 Procedure 5.1 Products in powder form The procedure specified is applicable to powders, including spray-dried powders, and particularly, those that
19、contain additives that have been introduced after the drying process. NOTE 1In the case of powders containing additives introduced after drying, the physical mixture obtained has a tendency to separate. NOTE 2In the case of washing powders, it is recommended that sampling be carried out under a vent
20、ilated hood; if necessary, a mask should be worn. 5.1.1 Apparatus Any satisfactory apparatus may be used, but the following types are recommended: 5.1.1.1 Conical divider (seeFigure 1 and Figure 2) The apparatus shall be constructed in such a way that the two portions of the sample obtained from eac
21、h dividing operation are quantitatively similar to each other and qualitatively representative of the original sample. 1) Definitions based on ISO6206.BS3762-1:1983 2 BSI 12-1999 An apparatus which satisfies these conditions is the conical divider (seeFigure 1) which consists essentially of a hopper
22、 (A) from which the sample to be divided runs over the surface of a cone (B) whose apex is situated directly beneath the centre of the lower opening in the hopper. The material running down the cone is diverted to series of receptacles arranged round the circumference of an inverted hopper (C) at th
23、e base of the cone (B). Alternate receptacles are connected to one or other of the two outlets at the bottom of the inverted hopper in order to provide two equivalent reduced samples. 5.1.1.2 Rotary sample divider (seeFigure 3) A suitable apparatus 2)comprises a hopper from which the sample falls in
24、 a thin stream onto a rotating platform carrying six, or more, identical receivers arranged symmetrically about the vertical axis of rotation so as to collect all of the falling sample. The frequency of rotation exceeds40min 1 . NOTETake care that the frequency of rotation of the platform is not too
25、 high if fine particles are present. 5.1.2 Preparation of the reduced sample using the conical divider(5.1.1.1) 5.1.2.1 Preparation of the final sample Place a receiver under each of the outlets of the conical divider. Fill the hopper and open the valve fully so as to allow the contents of the hoppe
26、r to run over the cone, thus dividing the bulk sample into two portions one of which is deposited in each receiver. Retain one of these portions and discard the other. Pass a fresh quantity of bulk sample through the conical divider and repeat the operation until all the bulk sample has been divided
27、. Clean the apparatus and again pass the retained portions, corresponding to half the bulk sample, through the apparatus as described above and repeat this operation until a reduced sample of the required mass has been obtained. 5.1.2.2 Preparation of several equivalent samples If more than one samp
28、le is required, prepare sufficient reduced sample to obtain2n equivalent samples where2n equals or exceeds the number of samples required. Subsequently, divide the reduced sample into2n equal portions by means of the conical divider. Immediately place the whole of each portion in an airtight bottle
29、or flask. 5.1.2.3 Preparation of test samples If test samples are required from the laboratory samples, treat the latter as specified in5.1.2.1 and5.1.2.2. The minimum mass of the test samples shall in no case be less than10g, otherwise there is a risk that the test samples may not be truly represen
30、tative of the bulk sample and, hence, will be unsuitable for test purposes. 5.1.3 Preparation of the reduced sample using the rotary divider(5.1.1.2) 5.1.3.1 Preparation of the final sample Place on the platform the complete set of receivers, one or more of which shall be clean and empty and shall b
31、ear some distinguishing mark. Fill the hopper. Set the rotating platform in motion and allow the bulk sample to fall into the receivers at a uniform rate for at least2min. Retain the portion collected in the marked receiver(s) and discard the remainder. If the mass of the bulk sample is greater than
32、 the capacity of the divider, carry out the division in a series of operations. At the end of each operation, combine the sample portion(s) from the marked receiver(s) in a larger container, and continue using the same marked receiver(s) for subsequent divisions until all the sample has been divided
33、. Transfer the material collected from the marked receiver(s) to the hopper, and repeat this operation until a sample of the required mass has been obtained. 5.1.3.2 Preparation of several equivalent samples If more than one sample is required, prepare sufficient reduced sample to obtain n equivalen
34、t samples, where n equals or exceeds the number of samples required. Select an appropriate number, n, of marked receivers, and pass all of the reduced sample through the rotary divider. Immediately place the whole of each portion in an airtight bottle or flask. 5.1.3.3 Preparation of test samples If
35、 test samples are required from the laboratory samples, treat the latter as specified in5.1.3.1 and5.1.3.2. The minimum mass of the test samples shall in no case be less than10g, otherwise there is a risk that the test samples may not be truly representative of the bulk sample. 2) Examples of commer
36、cially available apparatus are: Pascal Rotary cascade sample divider; Retsch type PT sample divider.BS3762-1:1983 BSI 12-1999 3 If the mass required is not a suitable fraction of the bulk sample, it may be necessary to combine portions from successive stages of the division. For example, to reduce a
37、 sample of280g to10g using six receivers, the first division with two marked receivers provides2 47g. One of the portions may again be divided and two of the resulting portions may be added to the remaining47g to give47+ 63g. Passing this through the apparatus a third time will give reduced samples
38、of approximately 10g. 5.2 Products in paste form 5.2.1 Apparatus 5.2.1.1 Scoop or spatula, for sampling. 5.2.1.2 Domestic mixer, provided with a beater, for blending. It is not possible to specify a mixer suitable for all requirements and any suitable mixer may be used. In general, it shall be suffi
39、ciently powerful so that, when used with a beater of suitable design, the whole of the bulk sample is mixed and a creamy mass attained within5min. 5.2.2 Preparation of a reduced sample Warm the product (bulk sample or laboratory sample) in its original container to35 to40 C, and mix immediately usin
40、g the domestic mixer(5.2.1.2) for2 to3min until a homogeneous mass is obtained. The paste shall not be removed from the original container before mixing as this may result in the production of a non-representative sample. It is therefore essential that the bulk sample is in a container which will al
41、low mixing without transfer. The heating and mixing times shall be as short as possible so as to reduce to a minimum any change in the product. Using the spatula or scoop(5.2.1.1), remove immediately the required quantity of sample and transfer it into an appropriate, previously tared container, fit
42、ted with a stopper. Allow the contents of the container to cool to ambient temperature, and reweigh to obtain the mass of the reduced sample. NOTEContact of the paste with glass vessels readily causes separation of a lye; therefore, once the sample is placed in the vessel, no part should be withdraw
43、n to adjust the mass. There is a slight loss of moisture during mixing and weighing but experience has shown that, in practice, this is at an acceptable level. 5.3 Liquid products 5.3.1 Apparatus 5.3.1.1 Glass flasks or weighing pipettes, for sampling. 5.3.1.2 Manual stirrer (for example, a glass ro
44、d). 5.3.1.3 Mechanical stirrer 5.3.2 Preparation of a reduced sample 5.3.2.1 If the product (bulk sample or laboratory sample) is clear and apparently homogeneous, mix it with the manual stirrer(5.3.1.2); then, using the flask or weighing pipette (5.3.1.1), remove immediately the quantity required f
45、or the reduced sample. As little foam as possible shall be produced in the sample during mixing, and any loss of sample by evaporation shall be kept to a minimum. 5.3.2.2 If the product (bulk sample or laboratory sample) is cloudy or contains a sediment, mix it using the mechanical stirrer(5.3.1.3);
46、 then remove immediately the required quantity of sample. 5.3.2.3 If the product (bulk sample or laboratory sample) contains a solid deposit, carefully warm the original container to about30 C until the sediment can be completely dispersed by stirring or until any crystals disappear, and remove imme
47、diately the required quantity of sample. 6 Storage of the reduced sample It is preferable for the analysis or test to be carried out as soon as possible after sampling but, if this is not possible and according to the intended purpose of the reduced sample, place it immediately in an airtight bottle
48、 or flask of glass or plastics materials and determine and record its mass. (Do not use metal containers.) Take care that the reduced sample is preserved as far as possible in its original condition until the analysis or test is carried out. 7 Report The report shall contain the following informatio
49、n: a) reference to the method used; b) the number of types of samples prepared and their mass at the time they were taken; c) the type of apparatus used; d) any unusual features noticed during the division procedures; e) any operation not included in this International Standard or regarded as optional. 2 6 -47 BS3762-1:1983 4 BSI 12-1999 Figure 1 Exploded view of a typical conical dividerBS3762-1:1983 BSI 12-1999 5 NOTEDimensions are given for guidance only. Figure 2 Diagram of a typical conical dividerBS3762-1:1983 6 BSI 12-1999 Figure 3 P
