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1、BRITISH STANDARD BS 5666-6: 1983 Incorporating Amendment No. 1 Methods of analysis of Wood preservatives and treated timber Part 6: Quantitative analysis of preservative solutions and treated timber containing pentachlorophenol, pentachlorophenyl laurate, -hexachlorocyclohexane and dieldrin NOTEIt i
2、s essential that this Part is read in conjunction with Part 1 “General considerations and sampling and preparation of materials for analysis”. UDC 674.048:630* 841:543.062 BS 5666-6:1983 This British Standard, having been prepared under the direction of the Wood Preservation Standards Committee, was
3、 published under the authority of the Board of BSI and comes into effect on 30 November 1983 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference WPC/11 Draft for comment 81/53056 DC ISBN 0 580 13548 9 Committees responsible for this British Standard The
4、preparation of this British Standard was entrusted by the Wood Preservation Standards Committee (WPC/-) to Technical Committee WPC/11 upon which the following bodies were represented: Association of Consulting Scientists British Drier Manufacturers Association British Wood Preserving Association Dep
5、artment of the Environment (Building Research Establishment, Princes Risborough Laboratory) Ministry of Defence Amendments issued since publication Amd. No.Date of issueComments 6224December 1989 Indicated by a sideline in the margin BS 5666-6:1983 BSI 11-1999i Contents Page Committees responsibleIn
6、side front cover 1Scope and field of application1 2Method I. Gas-liquid chromatographic method1 3Method II. Colorimetric method8 4Test report11 Publications referred toInside back cover BS 5666-6:1983 ii BSI 11-1999 A British Standard does not purport to include all the necessary provisions of a con
7、tract. 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 inside front cover, pages i and ii, pages 1 to 12, an inside back
8、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. BS 5666-6:1983 BSI 11-19991 1 Scope and field of application This Part of BS 5666 describes procedures for th
9、e quantitative determination of pentachlorophenol (PCP), pentachlorophenyl laurate (PCPL), -hexachlorocyclohexane (-HCH) and dieldrin present in preservative solutions and treated wood. Both colorimetric and gas-liquid chromatographic (GLC) methods are given for the determination of PCP and PCPL but
10、 only a GLC method is given for the determination of -HCH and dieldrin as no suitable specific chemical methods are available for these chlorinated hydrocarbon insecticides. The GLC method is suitable for the determination of the total amount of PCP, PCPL, -HCH and dieldrin within a single sample of
11、 wood. It may be used to study the distribution of these components through such a sample. Since the preservative solution, or the solution obtained by extraction of treated timber, is diluted to a suitable concentration for analysis, a wide range of concentrations may be assessed. In treated timber
12、, at the lower end of the range, loadings down to 0.001 % (m/m) have been determined by this method. However, at very low loadings, where little or no dilution is required, it is necessary to consider the possibility of interference from what are normally minor constituents of the system (e.g. wood
13、extractives or solvent impurities). The colorimetric method is suitable for the determination of PCP or PCPL in solutions or extracts from treated timber containing -HCH, dieldrin, tributyltin oxide (TBTO), copper naphthenate, zinc naphthenate, disodium octaborate and wood extractives. NOTEThe title
14、s of the publications referred to in this standard are listed on the inside back cover. CAUTION. Attention is drawn to the general safety precautions mentioned in clause 4 of Part 1 of this British Standard and also to the specific hazard warnings given in 2.2.7, 2.2.12 and 2.3.2 of this Part. 2 Met
15、hod I. Gas-liquid chromatographic method 2.1 Principle. PCP is extracted from treated wood with ethanol and preservative solutions containing PCP are diluted with ethanol before being methylated with diazomethane to produce pentachlorophenyl methyl ether. The resultant solutions are further diluted
16、with hexane. -HCH and dieldrin are extracted from treated wood with ethanol and preservative solutions containing -HCH and dieldrin are diluted with ethanol before being further diluted with hexane. Preservative solutions containing PCPL are saponified with morpholine and subsequently acidified to p
17、roduce free PCP. For treated wood, the saponification is accomplished using morpholine as the extractant. The PCP is extracted into xylene and diluted with ethanol. Methylation and further dilution follow as for PCP. The active components in all diluted solutions are determined using GLC with an ele
18、ctron-capture detector. Aldrin is used as an internal standard for PCP and -HCH, and 2,2-bis (4-chlorophenyl)-1,1-dichloroethylene (p,pDDE) is similarly used for dieldrin. 2.2 Reagents. All reagents shall be of recognized analytical reagent quality and water complying with BS 3978 shall be used thro
19、ughout. Check the solvents for purity by passing samples through the chromatograph under the conditions of the determination. If a response is obtained on the chromatogram that is likely to cause significant errors in the determination on the test sample, redistil the solvent until a satisfactory re
20、sponse is obtained. 2.2.1 Hexane 2.2.2 Ethanol, complying with BS 507 or industrial methylated spirits, complying with BS 35911). 2.2.3 Morpholine 2.2.4 Xylene 2.2.5 Hydrochloric acid, concentrated ( = 1.18 g/mL). 2.2.6 Sodium hydroxide solution, c(NaOH) = 0.1 mol/L approximately. Dissolve 4 g of so
21、dium hydroxide in 1 L of water. 1) The ethanol used as a reagent in this determination may be replaced for this purpose by industrial methylated spirits, 95 % (V/V), complying with BS 3591. It should be noted that the use of industrial methylated spirits is governed by the Methylated Spirits Regulat
22、ions 1983 (S.I. 1983, No. 252). It is not permissible to use duty-free ethanol, received under the provisions of the Alcoholic Liquors Duties Act 1979, Section 10, for purposes for which industrial methylated-spirits is an acceptable alternative to ethanol. BS 5666-6:1983 2 BSI 11-1999 2.2.7 Diazome
23、thane solution2). Prepared as follows. Dissolve 0.9 g of potassium hydroxide in 22 mL of ethanol (2.2.2) and add the solution slowly to a solution of 5 g of N-methyl-N-nitrosotoluene-4-sulphonamide in 70 mL of diethyl ether at 0 C. Allow the resulting solution to stand for 5 min, transfer the flask
24、containing the reaction mixture to a water bath and fit an efficient water-cooled condenser. Raise the temperature of the water bath to distil over the contents of the flask and collect the distillate in a flask cooled to below 30 C. Continue the distillation until the reaction mixture appears colou
25、rless. The yellow distillate is an ethereal solution of diazomethane. NOTEDiazomethane can also be prepared from N-methyl-N-nitro-N-nitrosoguanidine and aqueous alkali. (See Anal. Chem., 1973, 45, 2302.) WARNING. Diazomethane is highly toxic and solutions may explode on contact with ground glass joi
26、nts, sharp glass edges or in direct sunlight. It is imperative that all work involving diazomethane up to the final dilution is carried out behind a safety shield in an efficient fume cupboard. A diazomethane generator with smooth edges and joints throughout is commercially available and is recommen
27、ded. It is essential that the preparation and use of diazomethane is carried out only by properly trained personnel. 2.2.8 Standard aldrin solution, 1 mg/L. Weigh 0.1000 g of aldrin into a 100 mL one-mark volumetric flask. Add approximately 50 mL of ethanol (2.2.2), shake well to dissolve and make u
28、p to the mark with ethanol. Dilute 5 mL of this solution to 100 mL in a one-mark volumetric flask with hexane (2.2.1). Shake well and similarly dilute 5 mL of this solution to 250 mL in a one-mark volumetric flask. 2.2.9 Standard PCP solution, 1 mg/L. Weigh 0.1000 g of PCP, 99 % pure3), into a 100 m
29、L one-mark volumetric flask. Add approximately 50 mL of ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute 5 mL of this solution to 100 mL in a one-mark volumetric flask using the same solvent. Shake well and similarly dilute 5 mL of this solution to 250 mL in a one
30、-mark volumetric flask. 2.2.10 Standard -HCH solution, 0.1 mg/L. Weigh 0.1250 g of -HCH and transfer quantitatively to a 500 mL one-mark volumetric flask, washing-in with ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute 5 mL of this solution to 250 mL in a one-mar
31、k volumetric flask using hexane (2.2.1). Shake well and similarly dilute 5 mL of this solution to 250 mL in a one-mark volumetric flask. 2.2.11 Standard p,p-DDE solution, 0.25 mg/L. Weigh 0.1250 g of p,p-DDE into a 100 mL one-mark volumetric flask. Add approximately 50 mL of ethanol (2.2.2), shake w
32、ell to dissolve and make up to the mark with ethanol. Dilute 5 mL of this solution to 250 mL with hexane (2.2.1) in a 250 mL one-mark volumetric flask. Shake well and similarly dilute 5 mL of this solution to 500 mL in a one-mark volumetric flask. 2.2.12 Standard HEOD solution (for dieldrin analysis
33、), 0.1 mg/L. Weigh 0.1250 g of 1,2,3,4,10,10-hexachloro-6,7- epoxy-1,4,4a,5,6,7,8,8a-octahydro-exo-1,4, -endo-5,8,-dimethanonaphthalene, (HEOD)4) and transfer quantitatively to a 500 mL one-mark volumetric flask, washing in with ethanol (2.2.2), shake well to dissolve and make up to the mark with et
34、hanol. Dilute 5 mL of this solution to 250 mL in a one-mark volumetric flask with hexane (2.2.1). Shake well and similarly dilute 5 mL of this solution to 250 mL in a one-mark volumetric flask. WARNING. All of the organochlorine compounds referred to in 2.2.8 to 2.2.12 are toxic and have to be handl
35、ed with care to avoid ingestion or skin contact. p,p-DDE is a suspected carcinogen. 2.3 Apparatus 2.3.1 Volumetric glassware, complying with the requirements for class A of BS 1583 or BS 1792, as appropriate. 2.3.2 Electron-capture detector gas-liquid chromatograph with the following characteristics
36、: a) column temperature 170 C; b) detector temperature 250 C; c) glass-lined injector zone, with silicone rubber septum and maintained at 190 C to 200 C; d) glass column, approximately 1.5 m in length and 4 mm i.d., packed with 80-100 mesh (50 4m to 175 4m) chromosorb W AW/DMCS carrying 5 % of QF 1
37、and fitted with a silanized glass-wool plug at its head5); e) detector type, 63Ni electron-capture detector, pulsed-mode or direct current type; f) suitable recorder. WARNING. The electron-capture detector contains radioactive material and it is essential that it is used in accordance with the manuf
38、acturers instructions. 2) For reference see A.I. Vogel A textbook of practical organic chemistry, p291, Longmans 1978. 3) Technical PCP normally contains about 86 % pentachlorophenol. 4) Technical dieldrin contains a minimum of 85 % HEOD. 5) This plug is fitted to absorb unmethylated PCP. BS 5666-6:
39、1983 BSI 11-19993 2.3.3 Micro-pipette, syringe type, suitable for accurately injecting 1 4L, and with a needle length so that on-column injection is avoided. 2.3.4 Carrier gas, nitrogen flowing at a rate of 75 mL/min, dried by passage through a molecular sieve before entering the column. NOTEAn argo
40、n/methane mixture is also suitable for use with a pulsed mode detector. 2.3.5 Soxhlet apparatus complying with BS 2071. 2.4 Procedure 2.4.1 Preparation of the column. Condition the column using nitrogen as the carrier gas for about two days at a temperature of approximately 225 C with the detector d
41、isconnected. 2.4.2 Instrument setting and operation. Operate the instrument in accordance with the requirements stated in 2.3.2. NOTEUsing these conditions the following retention times are typical of those obtained: Changes in the oven temperature, gas flow rate and column dimensions may be made to
42、 vary the retention times according to the operators requirements. However, it is important that complete resolution of the peaks is attained. 2.4.3 Preparation of calibration solutions NOTEThe calibration solutions prepared as described in this clause are stable for limited periods only and it is r
43、ecommended that working standards are freshly prepared. 2.4.3.1 Methylation of the PCP standard solution. Pipette 10 mL of PCP standard solution (2.2.9) into a 50 mL conical flask and add diazomethane solution (2.2.7) until the yellow colour persists. Leave for at least 2 h and, if the yellow diazom
44、ethane is still present, gently warm the solution in the fume cupboard until colourless. Transfer the solution quantitatively to a 100 mL one-mark volumetric flask and make up to the mark with hexane (2.2.1). 2.4.3.2 PCP calibration solutions. Pipette 1 mL, 2 mL, and 3 mL of the methylated standard
45、PCP solution (2.4.3.1) into 10 mL one-mark volumetric flasks, add 1 mL of standard aldrin solution (2.2.8) (see note 1) to each and make up to the mark with hexane (2.2.1). These calibration solutions contain 0.01 mg/L, 0.02 mg/L and 0.03 mg/L PCP respectively. NOTE 1It is recommended that the same
46、pipette should always be used for the addition of the solution used as the internal standard. NOTE 2These concentrations and others used in the determinations of -HCH and dieldrin have been found to be suitable for a pulsedmode 63Ni electron-capture detector. Instruments using direct current detecto
47、rs may require the use of solutions about ten times more concentrated. It is important, however, that manufacturers instructions regarding the maximum amount of organochlorine compounds to be injected are followed. 2.4.3.3 -HCH calibration solutions. Pipette 1 mL, 2 mL and 3 mL of standard HCH solut
48、ion (2.2.10) into 10 mL one-mark volumetric flasks, add 1 mL of standard aldrin solution (2.2.8) (see note 1 to 2.4.3.2) to each and make up to the mark with hexane (2.2.1). These calibration solutions contain 0.01 mg/L, 0.02 mg/L and 0.03 mg/L -HCH respectively. 2.4.3.4 HEOD calibration solutions (
49、for dieldrin analysis). Pipette 1 mL, 2 mL and 3 mL of standard HEOD solution (2.2.12) into 10 mL one-mark volumetric flasks, add to each 1 mL of standard p,p-DDE solution (2.2.11) (see note 1 to 2.4.3.2) and make up to the mark with hexane (2.2.1). These calibration solutions contain 0.01 mg/L, 0.02 mg/L and 0.03 mg/L HEOD respectively. 2.4.4 Preparation of calibration graphs NOTE 1It is important with this and all other determinations that the volumetric flasks are shaken immediately before the sample for injection is taken. NOTE 2It is importan
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