DIN EN ISO 23161-2011 Soil quality - Determination of selected organotin compounds - Gas-chromatographic method (ISO 23161 2009) German version EN ISO 23161 2011《土壤质量 用气相色谱测定法测定所选的.pdf

1、October 2011 Translation by DIN-Sprachendienst.English price group 17No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).IC

2、S 13.080.10!$u 80 % of the internal standards and target compounds shall be achieved for each clean-up step. 5.5.2 Silica gel for the clean-up column Heat silica gel (5.2.6) for at least 12 h at (500 20) C on a quartz plate in a muffle furnace. Ensure that the temperature does not exceed 520 C. Allo

3、w the plate to cool in an oven to about 200 C, transfer the silica to a wide-necked glass bottle and allow cooling to room temperature in a desiccator. Add water to the cooled silica until a mass fraction of 3 % is reached. Close the bottle and homogenize the contents for 2 h on a shaker. 5.5.3 Alum

4、inium oxide for the clean-up column Activate aluminium oxide (5.2.7) by heating to 600 C for a minimum of 24 h. Allow to cool in the oven to about 200 C, transfer the aluminium oxide to a wide-necked glass bottle and allow cooling to room temperature in a desiccator. Add water to the cooled aluminiu

5、m oxide until a mass fraction of 10 % is reached. Close the bottle and homogenize the contents for 2 h on a shaker. 5.5.4 Clean-up column Add about 5 g of adsorbent (5.5.2 or 5.5.3) to one column, and add about 3 g of drying agent. Ensure that the clean-up column is filled homogeneously, for example

6、, by using hexane as a moistening agent during the filling process. Commercially pre-packed columns may be used as an alternative if the requirement for recovery is met. 5.5.5 Eluent for extract cleaning with silica gel A mixture of hexane (5.2.10) with a more polar solvent can be used as an eluent

7、to obtain a quantitative elution of all organotin compounds. In routine work, about 5 % of acetone (5.2.9) or 20 % of dichloromethane (5.2.13) was used successfully. The concentration of polar solvent in hexane and the volume of total eluent should be determined prior to application. 5.5.6 Eluent fo

8、r extract cleaning with aluminium oxide Generally, hexane (5.2.10) is used as the eluent. The volume of the eluent should be determined prior to application. 6 Apparatus 6.1 Requirements for glassware Customary laboratory glassware shall be used. All glassware and material that comes into contact wi

9、th the sample or extract shall be thoroughly cleaned. DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 11 6.2 Sampling apparatus Sampling devices shall not be a source of contamination. The use of stainless steel, glass or PTFE is recommended. NOTE For example, poly(vinyl chloride) (PVC) can contain l

10、arge amounts of organotin compounds. Containers shall be inert and appropriate for storing and transport. The size of the container shall be appropriate to ensure sampling of a suitable amount of solid to provide a representative sample and facilitate a determination in accordance with this Internat

11、ional Standard within the calibrated working range. 6.3 Additional apparatus Use ordinary laboratory apparatus and the following. 6.3.1 Centrifuge. WARNING The use of organic solvents in centrifuges needs to be assessed for safety reasons. 6.3.2 Glass column for clean-up, e.g. length 15 cm, inner di

12、ameter 1 cm, with frit, without a cock. 6.3.3 Shaker. 6.3.4 Ultrasonic bath or horn-type transducer. 6.3.5 Analytical balance, with suitable reading accuracy and range. 6.3.6 Concentration apparatus, e.g. rotary evaporator, Kuderna Danish. 6.3.7 Gas chromatograph, equipped with a high-resolution cap

13、illary column of suitable polarity and Injector, split or splitless, preferably with an automated sampling device (C.1). 6.3.8 Detectors (for typical detector configurations, see C.2). The following detector types may be used for the measurement of alkylated organotin compounds: atomic absorption sp

14、ectrometer (AAS), quartz oven, tin(Sn) lamp; flame photometric detector (FPD), equipped with a cut-off filter of 590 nm or interference filter of 610 nm; pulsed flame photometric detector (PFPD) equipped with a large pass-band filter working at 610 nm or 390 nm with a time-selective acquisition; mas

15、s spectrometer (MS) for electron impact mode (EI-mode); atomic emission detector (AED); inductively coupled plasma/mass spectrometric detector (ICP/MS). 6.3.9 Data processing system, suitable for the respective detector for acquisition and data evaluation. 7 Procedure 7.1 Sampling and sample pretrea

16、tment Sample pretreatment should be carried out according to ISO 14507 4or ISO 16720. The use of, for example, stainless steel, PTFE and glass is recommended. Store the sample until pretreatment in a cool place. DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 12 If the storage time is less than 48 h,

17、 store the sample in a dark, cool place until pretreatment. If the storage time exceeds 48 h, the sample shall be stored frozen ( 80 % of the internal compounds is achieved for each clean-up step. The reference and blank solutions shall be treated in the same way. NOTE 1 Triphenyltin elutes later fr

18、om the clean-up column than the other organotin compounds. If TPHT is not to be analysed, the clean-up efficiency can be improved by reducing the eluent volume, the water content of the adsorbent or the concentration of the polar solvent in hexane. NOTE 2 Boroxins will be formed during derivatizatio

19、n, which can affect the gas chromatography (GC) column. These are eliminated by silica clean-up with hexane, but can be eluted if acetone is added to the eluent. An alternative separation method is to shake with sodium hydroxide (NaOH) solution; peralkylated organotin compounds are stable against Na

20、OH solution. 7.3.2 Silica and aluminium oxide clean-up Rinse the clean-up column, freshly prepared in accordance with 5.5.4 with 30 ml of hexane (5.2.10). Transfer the concentrated extract in hexane to the clean-up column (5.5.4). After the extract has penetrated the top of the adsorbent layer, caut

21、iously add the volume of eluant (5.5.5 or 5.5.6) found to be necessary. Collect the eluate and reduce the volume of the organic phase to 1 ml using a suitable apparatus, but avoid reduction to dryness in every case. If the chromatography turns out to be unacceptable, apply further clean-up procedure

22、s (see Annex B). DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 14 7.4 Determination of dry mass Determine the fraction of dry mass gravimetrically in accordance with ISO 11465. The fraction of dry mass of original field-moist samples or of freeze-dried materials is expressed as a percentage. NOTE T

23、he following standards can be used for other solids: EN 12880 for sediments or sludges; EN 14346 for wastes. 7.5 Measurement 7.5.1 Gas chromatographic separation Optimize the instrument in accordance with the manufacturers instructions. Ensure at least baseline separation of the target peaks of inte

24、rest. Higher resolution is recommended to avoid co-elution of matrix compounds as far as appropriate (for typical gas chromatographic conditions, see C.1). The resolution of triphenylethyltin and tricyclohexylethyltin should be at least 0,8. Prepare injection solutions of blanks, references and samp

25、les by adding, for example, 50 l of injection standard (see 5.4.1) to the final extract of 1 ml. Inject an appropriate volume of the prepared sample extracts into the injection port of a gas chromatograph. Record retention times and the signal intensity of each compound. Quantify the gas chromatogra

26、phic signals either as peak areas or as peak heights. In the case of non-continuous detection (e.g. mass spectrometry), evaluation using peak areas is recommended. NOTE In this International Standard, only the evaluation using peak areas is described as an example. 7.5.2 Detection and identification

27、 Use an appropriate detector (see 6.3.8) for monitoring the target peaks. Independent from the detection system, identify the analytes by comparison of the retention times for samples and references. Minimal requirements for identification are retention times within 0,02 min and relative retention t

28、imes within 0,1 % over the total run of a chromatogram. Following the retention time criteria, three identification points are necessary. For GC/MS, this procedure is described in ISO 22892; each individual mass meeting the criteria gives one identification point. Identification points for other det

29、ectors are described in Table 4. If the detector does not give three identification points, additional points can be obtained by, for instance, using a second column or by pattern recognition (see also ISO 22892). Table 4 Identification points Detector Number of identification points Remarks FPD, PF

30、PD 2 MS 1 for each individual mass Refer to ISO 22892 MS/MS 2 for each mass transfer MSn1 for each mass transfer AED 3 Different spectral lines ICP/MSAAS 3 DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 15 8 Calibration Calibration is carried out by putting standards, including internal standards, t

31、hrough the whole procedure. The underivatized organotin compounds are added to water to give the aqueous calibration solutions (5.4.3). The whole procedure of derivatization, extraction, clean-up and concentration is carried out to establish calibration curves. At least six calibration solutions at

32、different concentrations should be used to prepare the calibration curve. For quantification of monobutyltin and monooctyltin compounds, use monoheptyltin trichloride (MHTCl) as the internal standard; for dibutyltin and dioctyltin compounds, use diheptyltin dichloride (DHTCl) as the internal standar

33、d; and for tributyltin, triphenyltin and tricyclohexyltin compounds, use tripropyltin chloride (TPTCl) as the internal standard. The recovery of the internal standards corresponding to each group of organotin compounds is to be checked to verify complete derivatization and extraction. For quantifica

34、tion of tetrabutyltin use tetrapropyltin (TTPT) as the internal standard. Derive from the chromatograms, by integration, the peak areas of the organotin cation derivates, TTBT and the internal standards. Calculate, for each organotin cation and TTBT, a calibration curve according to Equation (1) for

35、 each working range, using the least-squares linear regression 10yaxa=+ (1) where x is the ratio of the masses of organotin cation, respectively TTBT (mi) and the corresponding internal standard (mI) in the reference solution; Iimxm= (2) a1is the slope of the calibration curve; y is the ratio of the

36、 peak areas of organotin cation derivates or TTBT and the corresponding internal standard in the chromatograms of the calibration solutions; a0is the intercept of the calibration curve. 9 Recovery rates of the internal standard compounds The recoveries facilitate the recognition of bias caused by th

37、e procedure or by the matrix of the sample, allowing indications of the reliability of the procedure to be derived. Examples are shown in Annex A, Table A.1 (A D) to assist in the assessment of possible causes and effects. These recoveries are not to be used for the calculation of results. They shou

38、ld be at least 80 % for derivatization/extraction and again 80 % for each clean-up step, with a minimum of 50 % for the overall recovery. The injection standard tetrapentyltin (TTPeT) is used as the internal standard for the calculation of the recovery rates of the other internal standards. The rati

39、os of the signal response of each of the four internal standards and the tetrapentyltin in the six calibration chromatograms (the relative response factors, RRF) are calculated according to Equation (3). ITTPeTTTPeT IRRFAmA m=(3) DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 16 where AIis the peak

40、area of the internal standard, I; mIis the mass of the internal standard, I; ATTPeTis the peak area of the injection standard; mTTPeTis the mass of the injection standard. The mean of the relative response factors for each internal standard is taken as the reference value of recovery = 100 %. The re

41、lative response factors of these internal standards have to be calculated in the same manner as for the sample materials and thus measure the recoveries of the four internal standards. The recovery of a single internal standard (Rec) is calculated according to Equation (4). I sampleI calRRFRec 100RR

42、F= (4) where RRFI sampleis the relative response factor of the internal standard, I, of the sample; RRFI calis the mean relative response factor of the internal standard, I, of the calibration. 10 Quantification Calculate the mass miof organotin cation or TTBT (analyte i) in the sample extract accor

43、ding to Equations (5) to (7). 01yaxa= (5) Iimxm= (6) IiAyA= (7) where a1is the slope of the calibration curve; a0is the intercept of the calibration curve; A is the peak area of analyte i or of internal standard I in the sample chromatogram; m is the mass of analyte i or of internal standard I in th

44、e sample taken; y is the ratio of the peak areas of organotin cation derivates i or of TTBT and the corresponding internal standard I in the sample chromatograms. DIN EN ISO 23161:2011-10 EN ISO 23161:2011 (E) 17 Calculate the mass fraction of analyte i in the solid sample, in micrograms per kilogra

45、m (g/kg) dry mass, according to Equation (8). iimwE= (8) where wiis the mass fraction of the analyte i in the solid, in micrograms per kilogram (g/kg) or nanograms per gram (ng/g), respectively; miis the mass of analyte i in the pretreated sample portion, in nanograms (ng); E is the dry mass of samp

46、le taken, in grams (g). 11 Expression of results Report the mass fraction, in micrograms of analyte i (organotin cation or TTBT) per kilogram of dry solid (g/kg), to the nearest whole number and with two significant digits. 12 Precision Precision data of four soil and soil-like materials are include

47、d in Annex E. 13 Test report The test report shall contain the following details: a) a reference to this International Standard; b) a complete identification of the sample; c) information on sampling, storage and pretreatment; d) a detailed description of the procedure (e.g. extraction method, extra

48、ct cleaning, type of detector); e) the results of the determination; f) the determined recoveries of the internal standards; g) any details not specified in this International Standard or which are optional, as well as any factor which may have affected the results. DIN EN ISO 23161:2011-10 EN ISO 2

49、3161:2011 (E) 18 Annex A (informative) Information about the procedure A.1 Derivatization agent A simple and rapid synthesis of a suitable derivatization agent is published in Reference 13 in the Bibliography. Attach a stirrer, reflux condenser and a dropping funnel with inert-gas supply to a three-necked round-bottomed flask. Add 14,19 g of BF3OEt2, 9,72 g of Mg and 75 ml of THF to the round-bottomed flask. Add, by means of the dropping funnel, 43,59 g of ethylchloride while stirring. Stir for 2 h. Let the phases separate. The resulting supernatan