1、 IT IS THE USERS RESPONSIBILITY TO ESTABLISH APPROPRIATE PRECAUTIONARY PRACTICES AND TO DETERMINE THE APPLICABILITY OF REGULATORY LIMITATIONS PRIOR TO USE. EFFECTIVE HEALTH AND SAFETY PRACTICES ARE TO BE FOLLOWED WHEN UTILIZING THIS PROCEDURE. FAILURE TO UTILIZE THIS PROCEDURE IN THE MANNER PRESCRIB
2、ED HEREIN CAN BE HAZARDOUS. SAFETY DATA SHEETS (SDS) OR EXPERIMENTAL MATERIAL SAFETY DATA SHEETS (EMSDS) FOR ALL OF THE MATERIALS USED IN THIS PROCEDURE SHOULD BE REVIEWED FOR SELECTION OF THE APPROPRIATE PERSONAL PROTECTION EQUIPMENT (PPE). COPYRIGHT 2011, 2013, 2017 UOP LLC. All rights reserved. N
3、onconfidential UOP Methods are available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, USA. The UOP Methods may be obtained through the ASTM website, www.astm.org, or by contacting Customer Service at serviceastm.org, 610.832.9555 FAX, or 610.832.95
4、85 PHONE. Trace Chloride, Fluoride, and Bromide in Liquid Organics by Combustion Ion Chromatography (CIC) UOP Method 991-17 Scope This method is for determining trace concentrations of chloride, fluoride, and bromide in liquid organics by Combustion Ion Chromatography (CIC). This method has a lower
5、limit of quantitation of 0.1 mg/kg (mass-ppm) for fluoride and chloride, and 0.2 mg/kg for bromide. References Instruction Manual for Automatic Quick Furnace, Model AQF-2100H, www.cosa- UOP Method 999, “Precision Statements in UOP Methods,” www.astm.org Outline of Method A reproducible volume of sam
6、ple is injected into a quartz boat. The boat is introduced into a multi-position horizontal furnace under controlled temperature and moisture. The sample is then combusted in a pyrohydrolytic, oxygen enriched environment. The halogens in the sample are converted to hydrogen halides and halogen gas.
7、These gases are then absorbed into an aqueous solution of constant volume. An aliquot of the solution is injected into an ion chromatograph (IC) where chloride, fluoride, and bromide are separated by anion exchange and measured by a conductivity detector with ion suppression. External standards are
8、used for quantitation. Apparatus References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Balance, semi-micro, capacity 220 g, readable to 0.00001 g at 81 g Chromatographic column, IonPac AS11-HC Analytical, 250-mm length by 4-mm ID,
9、Dionex, Thermo Fisher, Cat. No. 052960 Combustion system, equipped with AQF-2100H furnace (HF-210 horizontal furnace), GA-210 gas adsorption unit, ABC-210 automatic boat controller, ASC-250L liquid autosampler, and AQF Software, COSA Instrument Corp. Newer models from the same manufacturer are also
10、suitable. Deionized water system, Barnstead GenPure xCAD Plus UV TOC (bench version), Thermo Scientific, ThermoFisher Cat. No. 50136153 Dry block heater, digital, 2 block capacity, 120V, 50/60Hz, 210W, VWR, Cat. No. 12621-088, and heating blocks with 15- and 28-mm diameter vial wells, Cat. Nos. 1262
11、1-126 and -138, respectively 2 of 14 991-17 Flask, volumetric, 1-L, borosilicate glass, Class A, VWR, Cat No. 89000-412 Ion chromatograph, equipped with a pump, injection valve/autosampler, eluent generator, continuously regenerated trap column, suppressor, conductivity detector, computer, and Chrom
12、eleon software, Dionex, Thermo Fisher, Model ICS-2100 Muffle furnace, capable of operation at 800C, Barnstead/Thermolyne compact benchtop muffle furnace, Thermo Scientific, VWR Cat. No. 30631-230 Pipettor, Eppendorf Reference single-channel, variable volume, 100-1000 mL, VWR, Cat. No. 10032-682 Refr
13、igerator, laboratory, explosion proof or flammable storage, Fisher Scientific, Cat. No. 05EREETSA Regulator, argon, two-stage, high purity, delivery pressure range 30-700 kPa (4-100 psi), Matheson Tri-Gas, Model 3122-590 Regulator, oxygen, two-stage, high purity, delivery pressure range 30-700 kPa (
14、4-100 psi), cleaned for oxygen service, Matheson Tri-Gas, Model 3810-540 Ultrasonic bath, Electron Microscopy Sciences Model 3510-MT, VWR, Cat. No. 100493-068 Vortex mixer, digital, 120V, 30W, VWR, Cat. No. 97043-564 Reagents and Materials References to catalog numbers and suppliers are included as
15、a convenience to the method user. Other suppliers may be used. References to water mean deionized and distilled water that is subsequently treated to produce ionically pure, 18.2 megaohm-cm, organic-free (99.9%, VWR, Cat. No. BJ010 Adsorption tube, 10-mL, COSA Instrument Corp., Cat. No. MC25000 (rep
16、lacement) Argon, 99.999% pure Ball joint with U-shaped tube, COSA Instrument Corp., Cat. No. MC28017 (replacement) 4-Bromoacetanilide, 98% pure, Sigma-Aldrich, Cat No. 161659 4-Fluorobenzoic acid, 99+% pure, Sigma-Aldrich, Cat. No. 418846 Methanol, B then draw 80 L of sample/standard into the syring
17、e. 4. Place syringe on balance and weigh syringe. Record the weight to nearest 0.00001 g. For a sample that must be heated, weigh the heated syringe with sample and immediately dispense the contents. 5. Enter the weight in the chromatography software under the weight column for the associated sample
18、/standard. 6. Dispense weighed liquid into the waste bottle of the autosampler. 7. Rinse syringe with 3 syringe volumes of toluene. a. Repeat Steps 2-6 for all samples and standards. b. Proceed to Step 8 when all standards and samples have been weighed. 8. Return the clean syringe to the autosampler
19、 and proceed to Step 3 of Liquid Injection for liquid samples or Step 5 of Heated Sample Injection for viscous or waxy samples to start the analysis. Analysis of Standard Calibration Solutions 1. Fill sample vials with all four Standard Calibration Solutions and load them onto the liquid autosampler
20、. 2. Inject 80 L of Standard Calibration Solution 1 into the quartz boat of the automatic boat controller (ABC) and start the combustion and IC sequences. Identify and integrate each peak for the calibration standards. Identification can be aided by comparing to the typical standard chromatogram (se
21、e Figure). Individual standards may need to be prepared to identify retention times. Cumulative multiple injections in the absorption solution increase the effective concentration of the analytes of interest. For low concentrations, from 0.1-10 mg/kg, it is required to run 3 cumulative injections to
22、 increase the response of fluoride, chloride, and bromide. For concentrations from 10-1000 mg/kg, a single injection is sufficient. 3. Calculate the response factor for each analyte using the chromatography software or Equation 3 in Calculations. 4. Repeat Steps 3 and 4 with Standard Calibration Sol
23、utions 2, 3, and 4. Analysis of Blank Blank runs may be needed to check for interference or carryover from a previous analysis. 1. Start the combustion and IC process with an empty sample boat under the same burn program as the standards and/or samples. 2. Identify and integrate peak areas of intere
24、st. 3. If background peaks are higher than the lowest standard, run the default boat prebake method 10 of 14 991-17 five times and re-analyze another empty sample boat blank injection. If background is still high, remove the old quartz boat. Replace with a new quartz boat and quartz wool. Run five b
25、oat prebakes and then return to Step 1. Sample Analysis There are two types of injections listed below. Use Liquid Injection for samples that do not need to be heated prior to analysis. Use Heated Sample Injection for samples that are viscous or waxy at room temperature. Samples that are still visco
26、us after heating must be diluted with toluene. Liquid Injection 1. Proceed to Step 3 if the sample is not to be diluted. If the sample is to be diluted, weigh approximately 1 g of the sample into a 40 ml sample prep vial and record the weight to the nearest 0.00001 g. 2. Add approximately 9 g of tol
27、uene to the solution and record the total diluted weight to the nearest 0.0001 g. Cap the vial and vortex the sample solution for approximately 30 seconds so that the sample is thoroughly mixed. 3. Fill an autosampler vial with the sample or the diluted sample. 4. Inject 80 L of the sample into the
28、quartz boat and start the combustion and IC sequences. If accumulated injections were run on the standards, the exact same number of accumulated injections must be run on the samples, for example if three 80-L injections were made for the calibration standards, then three 80-L injections are require
29、d for the samples. 5. Identify each analyte by retention time (see Figure). Integrate the analyte peaks of interest to calculate the area response. 6. If the areas obtained for any of the analytes are above the highest standard, prepare quantitative serial dilution(s) of the sample. This is done by
30、diluting the sample or sample solution in toluene on a mass/mass basis until the resulting chromatographic analyte peak areas fit within the calibration standards. Record the weights of each serial dilution to the nearest 0.00001 g. Label as Serial Diluted Sample (X). Repeat Steps 3 and 4 of Liquid
31、Injection for the serially diluted sample(s). Heated Sample Injection 1. Turn on the digital block heater. The heater should not exceed 70-80C. 2. Place sample vial in heater block until sample is liquefied. 3. Remove the sample vial from heater block, uncap, and pour an aliquot into an autosampler
32、vial. 4. Place the autosampler vial into the vial heater to keep warm. 5. Slide the autosampler away from the injection port of the automatic boat controller and inject 80 L of sample directly into the quartz boat. Start the combustion and IC sequences. If accumulated injections were run on the stan
33、dards, the exact same number of accumulated injections must be run on the samples, for example, if three 80-L injections were made for the calibration standards, then three 80-L injections are required for the samples. Place the syringe on the heater block to warm up to the same temperature as the s
34、ample. This will prevent the sample from solidifying in the syringe when trying to inject into the quartz boat in the automatic boat controller. 6. Identify each analyte by retention time (see Figure). Integrate the analyte peaks of interest to calculate the area response. 11 of 14 991-17 7. If the
35、areas obtained for any of the analytes are above the highest standard, prepare quantitative serial dilution(s) of the sample. This is done by diluting the samples in toluene on a mass/mass basis until the resulting chromatographic analyte peak areas fit within the calibration standards. Record the w
36、eights of each serial dilution to the nearest 0.00001 g. Label as Serial Diluted Heated Sample (X). The vials may need to be heated to ensure the sample is completely dissolved. Weigh the syringe as described in Density Correction, and repeat Steps 4 and 5 in Heated Sample Injection for the serially
37、 diluted and heated samples. Calculations All calculations are performed by the instrument software and results are displayed and printed in mass-ppm (mg/kg). If the sample and standard vary in density, the masses of an 80-L liquid injection of the samples and standards are entered during sample dat
38、a entry to compensate for the difference. The calculations below are included for information and for single point manual calculation, if desired. Calculate the response factor for each analyte in the standard calibration solutions to three significant figures using Equation 4. NLM(4) where: L = con
39、centration of each analyte in each level of Standard Calibration Solution, mg/kg, as defined in Equation 3 M = response factor for each analyte N = analyte response area Calculate the dilution factor for each sample to three significant figures using Equation 5. Proceed to Equation 6 if the sample w
40、as not diluted. The dilution factor = 1 if no dilution was made. R =QP(5) where: P = total mass of sample and diluent (Liquid Injection, Step 2), g Q = total mass of sample weighed (Liquid Injection, Step 1), g R = dilution factor for diluted sample solution Calculate the ratio of standard weight in
41、jected to sample weight injected to three significant figures using Equation 6. U =TS(6) where: S = weight of standard injected T = weight of sample injected U = ratio of standard weight injected to sample weight injected Calculate each analyte concentration in the original sample to the nearest 0.1
42、 mg/kg, not to exceed two significant figures, using Equation 7. Concentration of analyte in sample or sample solution, mg/kg = ZWMRUV(7) where: M =response factor for each analyte, from Equation 4 R =dilution factor for diluted sample solution, from Equation 5 U =ratio of standard weight injected t
43、o sample weight injected, from Equation 6 V= Area of peak of each analyte in sample 12 of 14 991-17 W = final diluted sample mass (if serial dilution is needed), g Z =mass of IC sample stock solution aliquot (if serial dilution is needed), g If no serial dilution is required, W/Z = 1 Precision Preci
44、sion statements were determined using UOP Method 999, “Precision Statements in UOP Methods.” Repeatability and Site Precision A nested design was carried out for determining halogens in liquid organics by two analysts, with each analyst performing analyses on four samples on two separate days, perfo
45、rming two analyses each day for a total of 32 analyses. Using a stepwise analysis of variance procedure, the within-day and within-lab estimated standard deviations (esd) were calculated at the concentration means listed in Table 4. Two analyses performed in one laboratory by the same analyst on the
46、 same day should not differ by more than the repeatability allowable differences shown in Table 4 with 95% confidence. Two analyses performed in one laboratory by different analysts on different days should not differ by more than the site precision allowable differences shown in Table 4 with 95% co
47、nfidence. Table 4 Repeatability and Site Precision, mg/kg Repeatability Site Precision Component Mean Within- Day esd Allowable Difference Within- Lab esd Allowable Difference Chloride 0.1 0.01 0.1 0.01 0.1 Chloride 1.4 0.08 0.3 0.09 0.3 Chloride 10.7 0.25 1.0 0.35 1.4 Chloride 16.7 0.34 1.4 0.36 1.
48、4 Fluoride 0.1 0.01 0.1 0.01 0.1 Fluoride 0.6 0.11 0.4 0.21 0.9 Fluoride 8.8 0.12 0.5 0.41 1.9 Fluoride 13.8 0.49 1.9 0.49 2.5 Bromide 0.1 0.02 0.1 0.02 0.1 Bromide 1.3 0.14 0.6 0.14 0.6 Bromide 12.2 0.32 1.3 0.38 1.5 Bromide 17.8 0.36 1.4 0.52 2.0 The data in Table 4 represent short-term estimates
49、of the repeatability of the method. When the test is run routinely, use of a control standard and a control chart is recommended to generate an estimate of long-term repeatability. Reproducibility There is insufficient data to calculate the reproducibility of the test at this time. Time for Analysis The elapsed time for the preparation and analysis of one sample, including the analysis of a blank and calibration, is 2 hours. The labor requirement is 1 hour. Suggested Suppliers AccuStandard, 125 Market St., New Haven, CT 06513, US
