BS 5666-6-1983 Methods of analysis of wood preservatives and treated timber - Quantitative analysis of preservative solutions and treated timber containing pentachlorophenol pentac.pdf

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 “Generalconsiderations and sampling and preparation of materials for analysis”. UDC 674.048:630* 841:543.062BS5666-6:1983 This British Standard, having been prepared under the directionof the Wood PreservationStandards Committee, was publ

3、ished underthe authority of the BoardofBSI and comes intoeffecton 30November1983 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 preparation

4、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 Department of t

5、he Environment (Building Research Establishment, Princes Risborough Laboratory) Ministry of Defence Amendments issued since publication Amd. No. Date of issue Comments 6224 December 1989 Indicated by a sideline in the marginBS5666-6:1983 BSI 11-1999 i Contents Page Committees responsible Inside fron

6、t cover 1 Scope and field of application 1 2 Method I. Gas-liquid chromatographic method 1 3 Method II. Colorimetric method 8 4 Test report 11 Publications referred to Inside back coverBS5666-6:1983 ii BSI 11-1999 A British Standard does not purport to include all the necessary provisions of a contr

7、act. 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, pages1 to 12, aninside back cove

8、r 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.BS5666-6:1983 BSI 11-1999 1 1 Scope and field of application This Part of BS5666describes procedures for the quant

9、itative 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 only

10、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 wood.

11、 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, at t

12、he lower end of the range, loadings down to0.001% (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 extracti

13、ves 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 titles of the

14、 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 Part1of this British Standard and also to the specific hazard warnings given in 2.2.7, 2.2.12 and2.3.2 of this Part. 2 Method I. Gas-

15、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 with hexane

16、. -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 produce free

17、 PCP. For treated wood, thesaponification 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 electron-captur

18、e detector. Aldrin is used as an internal standard for PCP and -HCH, and2,2-bis (4-chlorophenyl)-1,1-dichloroethylene (p,pDDE) issimilarly used for dieldrin. 2.2 Reagents. All reagents shall be of recognized analytical reagent quality and water complying with BS3978shall be used throughout. Check th

19、e 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 response is obtain

20、ed. 2.2.1 Hexane 2.2.2 Ethanol, complying with BS507or industrial methylated spirits, complying with BS3591 1) . 2.2.3 Morpholine 2.2.4 Xylene 2.2.5 Hydrochloric acid, concentrated ( = 1.18g/mL). 2.2.6 Sodium hydroxide solution, c(NaOH) = 0.1mol/L approximately. Dissolve4g ofsodium hydroxide in1L of

21、 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 BS3591. It should be noted that the use of industrial methylated spirits is governed by the Methylated Spirits Regulations1983 (S.I. 1983, No. 2

22、52). It is not permissible to use duty-free ethanol, received under the provisions of the Alcoholic Liquors Duties Act1979, Section10, for purposes for which industrial methylated-spirits is an acceptable alternative to ethanol.BS5666-6:1983 2 BSI 11-1999 2.2.7 Diazomethane solution 2) . Prepared as

23、 follows. Dissolve0.9g of potassium hydroxide in22mL of ethanol (2.2.2) and add the solution slowly to a solution of5g of N-methyl-N-nitrosotoluene-4-sulphonamide in70mL of diethyl ether at0 C. Allow the resulting solution to stand for5min, transfer the flask containing the reaction mixture to a wat

24、er 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 below30 C. Continue the distillation until the reaction mixture appears colourless. The yellow distillate is an ethere

25、al solution of diazomethane. NOTEDiazomethane can also be prepared from N-methyl-N-nitro-N-nitrosoguanidine and aqueous alkali. (SeeAnal. Chem.,1973, 45, 2302.) WARNING. Diazomethane is highly toxic and solutions may explode on contact with ground glass joints, sharp glass edges or in direct sunligh

26、t. 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 recommended. It is essential that the preparation a

27、nd use of diazomethane is carried out only by properly trained personnel. 2.2.8 Standard aldrin solution, 1mg/L. Weigh0.1000g of aldrin into a100mL one-mark volumetric flask. Add approximately50mL of ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute5mL of this solu

28、tion to100mL in a one-mark volumetric flask with hexane (2.2.1). Shake well and similarly dilute5mL of this solution to250mL in a one-mark volumetric flask. 2.2.9 Standard PCP solution, 1mg/L. Weigh0.1000g of PCP, 99% pure 3) , into a100mL one-mark volumetric flask. Add approximately50mL of ethanol

29、(2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute5mL of this solution to100mL in a one-mark volumetric flask using the same solvent. Shake well and similarly dilute5mL of this solution to250mL in a one-mark volumetric flask. 2.2.10 Standard -HCH solution, 0.1mg/L. Weigh0.1

30、250g of -HCH and transfer quantitatively to a500mL one-mark volumetric flask, washing-in with ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute5mL of this solution to250mL in a one-mark volumetric flask using hexane (2.2.1). Shake well and similarly dilute5mL of th

31、is solution to250mL in a one-mark volumetric flask. 2.2.11 Standard p,p-DDE solution, 0.25mg/L. Weigh0.1250g of p,p-DDE into a100mL one-mark volumetric flask. Add approximately50mL of ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute5mL of this solution to250mL wit

32、h hexane(2.2.1) in a250mL one-mark volumetric flask. Shake well and similarly dilute5mL of this solution to500mL in a one-mark volumetric flask. 2.2.12 Standard HEOD solution (for dieldrin analysis), 0.1mg/L. Weigh0.1250g of1,2,3,4,10,10-hexachloro-6,7- epoxy-1,4,4a,5,6,7,8,8a-octahydro-exo-1,4, -en

33、do-5,8,-dimethanonaphthalene, (HEOD) 4)and transfer quantitatively to a500mL one-mark volumetric flask, washing in with ethanol (2.2.2), shake well to dissolve and make up to the mark with ethanol. Dilute5mL of this solution to250mL in a one-mark volumetric flask with hexane (2.2.1). Shake well and

34、similarly dilute5mL of this solution to250mL in a one-mark volumetric flask. WARNING. All of the organochlorine compounds referred to in2.2.8 to 2.2.12 are toxic and have to be handled with care to avoid ingestion or skin contact.p,p-DDE is a suspected carcinogen. 2.3 Apparatus 2.3.1 Volumetric glas

35、sware, complying with the requirements for class A of BS1583or BS1792, asappropriate. 2.3.2 Electron-capture detector gas-liquid chromatograph with the following characteristics: a) column temperature170 C; b) detector temperature250 C; c) glass-lined injector zone, with silicone rubber septum and m

36、aintained at190 C to200 C; d) glass column, approximately1.5m in length and4mm i.d., packed with80-100mesh (504m to1754m) chromosorb W AW/DMCS carrying5% of QF1and fitted with a silanized glass-wool plug at its head 5) ; e) detector type, 63 Ni electron-capture detector, pulsed-mode or direct curren

37、t type; f) suitable recorder. WARNING. The electron-capture detector contains radioactive material and it is essential that it is used in accordance with the manufacturers instructions. 2) For reference see A.I. Vogel A textbook of practical organic chemistry, p291, Longmans1978. 3) Technical PCP no

38、rmally contains about86% pentachlorophenol. 4) Technical dieldrin contains a minimum of85% HEOD. 5) This plug is fitted to absorb unmethylated PCP.BS5666-6:1983 BSI 11-1999 3 2.3.3 Micro-pipette, syringe type, suitable for accurately injecting14L, and with a needle length so that on-column injection

39、 is avoided. 2.3.4 Carrier gas, nitrogen flowing at a rate of75mL/min, dried by passage through a molecular sieve before entering the column. NOTEAn argon/methane mixture is also suitable for use with a pulsed mode detector. 2.3.5 Soxhlet apparatus complying with BS2071. 2.4 Procedure 2.4.1 Preparat

40、ion of the column. Condition the column using nitrogen as the carrier gas for about two days at a temperature of approximately225 C with the detector disconnected. 2.4.2 Instrument setting and operation. Operate theinstrument in accordance with the requirements stated in 2.3.2. NOTEUsing these condi

41、tions the following retention times are typical of those obtained: Changes in the oven temperature, gas flow rate and column dimensions may be made to vary the retention times according to the operators requirements. However, it is important that complete resolution of the peaks is attained. 2.4.3 P

42、reparation of calibration solutions NOTEThe calibration solutions prepared as described in this clause are stable for limited periods only and it is recommended that working standards are freshly prepared. 2.4.3.1 Methylation of the PCP standard solution. Pipette10mL of PCP standard solution (2.2.9)

43、 intoa50mL conical flask and add diazomethane solution (2.2.7) until the yellow colour persists. Leave for at least2h and, if the yellow diazomethane is still present, gently warm the solution in the fume cupboard until colourless. Transfer the solution quantitatively to a100mL one-mark volumetric f

44、lask and make up to the mark with hexane (2.2.1). 2.4.3.2 PCP calibration solutions. Pipette1mL,2mL, and3mL of the methylated standard PCP solution (2.4.3.1) into10mL one-mark volumetric flasks, add1mL of standard aldrin solution (2.2.8) (see note1) to each and make up to the mark with hexane (2.2.1

45、). These calibration solutions contain0.01mg/L, 0.02mg/L and0.03mg/L PCP respectively. NOTE 1It is recommended that the same 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 diel

46、drin have been found to be suitable for a pulsedmode 63 Ni electron-capture detector. Instruments using direct current detectors may require the use of solutions about ten times more concentrated. It is important, however, that manufacturers instructions regarding the maximum amount of organochlorin

47、e compounds to be injected are followed. 2.4.3.3 -HCH calibration solutions. Pipette1mL,2mL and3mL of standard HCH solution (2.2.10) into10mL one-mark volumetric flasks, add1mL of standard aldrin solution (2.2.8) (seenote1to2.4.3.2) to each and make up to the mark with hexane (2.2.1). These calibrat

48、ion solutions contain0.01mg/L, 0.02mg/L and0.03mg/L -HCH respectively. 2.4.3.4 HEOD calibration solutions (for dieldrin analysis). Pipette1mL, 2mL and3mL of standard HEOD solution (2.2.12) into10mL one-mark volumetric flasks, add to each1mL of standard p,p-DDE solution (2.2.11) (seenote1to2.4.3.2) a

49、nd make up to the mark with hexane (2.2.1). These calibration solutions contain0.01mg/L, 0.02mg/L and0.03mg/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 important that the measurement of the test solution and the calibration solutions should be carried out with the same settings of the chromatograph. Treat the test solution and the calibration solutions in