HJ 811-2016 English PDFUS$209.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. HJ 811-2016: Water quality. Determination of total selenium.3, 3′-Diaminobenzidine spectrophotometric method Status: Valid
Basic dataStandard ID: HJ 811-2016 (HJ811-2016)Description (Translated English): Water quality. Determination of total selenium.3, 3��-Diaminobenzidine spectrophotometric method Sector / Industry: Environmental Protection Industry Standard Classification of Chinese Standard: Z16 Word Count Estimation: 9,916 Date of Issue: 2016-07-26 Date of Implementation: 2016-10-01 Quoted Standard: HJ/T 91 Regulation (derived from): Ministry of Environmental Protection Notice No. 52 of 2016 Issuing agency(ies): Ministry of Ecology and Environment Summary: This standard specifies the determination of total selenium in water 3.3 "" - diaminobenzidine spectrophotometric method. This standard applies to the determination of total selenium in surface water, groundwater, domestic sewage and industrial waste water. When the sampling volume is 200 ml, the detection limit of this method is 2.0 ��g/L and the lower limit of determination is 8.0 ��g/L when using 30 mm cuvette. HJ 811-2016: Water quality. Determination of total selenium.3, 3′-Diaminobenzidine spectrophotometric method---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. Water quality.Determination of total selenium.3, 3'-Diaminobenzidine spectrophotometric method National Environmental Protection Standard of the People 's Republic of China Determination of total selenium in water quality 3,3'-diaminobenzidine spectrophotometry Water quality-Determination of total selenium -3,3'-Diaminobenzidine spectrophotometric method 2016-07-26 release 2016-10-01 implementation Ministry of Environmental Protection released Directory Preface ..II 1 Scope of application 1 2 normative reference document 1 3 Terms and DefinitionsPrinciple of Method 15 interference and elimination6 reagents and materials7 Instruments and equipment8 samples9 Analysis Step 3 Calculation and representation of results 4 11 Precision and Accuracy 5 12 Quality assurance and quality control 13 Waste treatment 5ForewordIn order to implement the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on the Prevention and Control of Water Pollution, Human health, regulate the determination of total selenium in water, the development of this standard. This standard specifies the determination of total selenium in surface water, groundwater, domestic sewage and industrial waste water 3,3'-diaminobenzidine spectrophotometry Degree method. This standard is the first release. This standard is organized by the Ministry of Environmental Protection Science and Technology Standards Division. The main drafting of this standard. Lanzhou City Environmental Monitoring Station. The standard verification unit. Gansu Province Environmental Monitoring Center Station, Chengdu Environmental Monitoring Center Station, Jinchang City Environmental Monitoring Station, China Oil Group Company Lanzhou Company Testing Center, Baiyin City Environmental Monitoring Station and Lanzhou University Analysis and Testing Center. The environmental protection department of this standard approved on July 26,.2016. This standard has been implemented since October 1,.2016. This standard is explained by the Ministry of Environmental Protection. Water quality - Determination of total selenium 3,3' - diaminobenzidine spectrophotometric method Warning. nitric acid and perchloric acid with strong corrosive and strong oxidizing, hydrochloric acid with strong volatility and corrosive, should be worn during operation Protective equipment, avoid contact with skin and clothing. The digestion of all samples should be carried out in a fume hood. Toluene and 3,3'-diamino Benzidine is a toxic reagent, the waste generated in the experiment should be collected and treated.1 Scope of applicationThis standard specifies the determination of total selenium in water 3,3'-diaminobenzidine spectrophotometric method. This standard applies to the determination of total selenium in surface water, groundwater, domestic sewage and industrial waste water. When the sampling volume is.200 ml, when the 30 mm cuvettes are used, the detection limit of this method is 2.0 μg/L and the lower limit of determination is 8.0 Μg/L.2 normative reference documentsThe contents of this standard refer to the following documents or their terms. Where a reference file is not dated, its valid version applies This standard. Technical specification for surface water and wastewater monitoring3 terms and definitionsThe following terms and definitions apply to this standard. 3.1 Total selenium Samples were digested after the determination of selenium, that is, the sum of organic selenium and inorganic selenium in the sample.4 principle of the methodAfter digestion with the mixed acid, the total selenium in the sample was reduced to tetravalent by hydroxylamine hydrochloride, and under acidic conditions with the color reagent 3,3'- (3,3'-Diaminobenzidine) to form a yellow compound, which was extracted with toluene at 420 nm Measure the absorbance at the wavelength. In a certain concentration range, the total selenium content and absorbance values in line with Lambert - Beer's law. Chemical reaction side The program is as follows.5 interference and eliminationCommon ions in water generally do not interfere with the determination of total selenium in this process. When the iron ion concentration is greater than 50 mg/L, (EDTA-2Na) mixed reagent to mask or eliminate the interference with ethylenediamine tetraacetic acid disodium.6 reagents and materialsUnless otherwise stated, analytical pure chemical reagents are used in accordance with national standards. Experimental water is a newly prepared deionized Water or distilled water. 6.1 hydrochloric acid. ρ (HCl) = 1.19 g/ml, excellent grade pure. 6.2 nitric acid. ρ (HNO3) = 1.42 g/ml, excellent grade pure. 6.3 perchloric acid. ρ (HClO4) = 1.67 g/ml, excellent grade pure. 6.4 Toluene. ρ (C7H8) = 0.87 g/ml, Pesticide level. 6.5 ammonia. ρ (NH3 · H2O) = 0.91 g/ml, excellent grade pure. 6.6 Sodium hydroxide (NaOH). 6.7 Ethylenediaminetetraacetic acid disodium dihydrate (C10H18N2Na2O10). 6.8 Hydroxylamine hydrochloride (NH2OH · HCl). 6.9 Cresol red (C21H18O5S). 6.10 selenium powder (grain). mass fraction ≥ 99.9%. 6.11 3,3'-diaminobenzidine tetrahydrochloride (C12H14N4 · 4HCl), excellent grade pure. 6.12 hydrochloric acid solution. 1 4 (v/v). Prepared with hydrochloric acid (6.1). 6.13 hydrochloric acid solution. c = 0.1 mol/L. Prepared with hydrochloric acid (6.1). 6.14 nitric acid solution. 1 1 (v/v). Prepared with nitric acid (6.2). 6.15 nitric acid - perchloric acid solution Mixed with an equal volume of nitric acid (6.2) and perchloric acid (6.3). 6.16 Sodium hydroxide solution. ρ = 100 g/L. Weigh 50 g of sodium hydroxide (6.6) in the appropriate amount of water, to be cooled, diluted to 500 ml. 6.17 Cresol red solution. ρ = 0.2 g/L. Weigh 20.0 mg of cresol red (6.9) in the appropriate amount of water, add 1 drop of ammonia (6.5), dissolved and transferred to 100 ml capacity Measuring bottle, the water volume to the mark, shake. 6.18 Ethylenediamine tetraacetic acid disodium mixed test solution Weigh 10.0 g of ethylenediaminetetraacetic acid disodium dihydrate (6.7) dissolved in water, dissolved in heat, cooled and added 10 ml Cresol red solution (6.17), the volume of water to.200 ml, shake. Stored in plastic bottles, refrigerated below 4 ℃, sealed can be saved Six months. 6.19 Ethylenediamine tetraacetic acid disodium mixed test solution Ethylenediamine tetraacetic acid disodium mixed test solution (6.18) diluted with water 10 times that is the use of liquid, with the current allocation. 6.20 Hydroxylamine Hydrochloride Solution. ρ = 20 g/L. Weigh 2.0 g hydroxylamine hydrochloride (6.8), dissolved in water, water volume to 100 ml, with the current allocation. 6.21 3,3'-diaminobenzidine tetrachloride solution. ρ = 5 g/L. Weigh 0.5 g of 3,3'-diaminobenzidine tetrachloride (6.11) in an appropriate amount of water and set to 100 ml with water. The solution Perishable, should be used with the current distribution. 6.22 Selenium standard stock solution. ρ = 100 mg/L. Accurate weighing 0.1 g (accurate to 0.0001 g) selenium powder (granules) (6.10) In a 100 ml beaker, add 10 ml nitric acid (6.2) Low temperature heating dissolved, add 2 ml of perchloric acid (6.3), in the hot plate slowly heated to the beaker filled with thick white smoke, Continue to heat until the white smoke gradually disappear to remove the nitric acid, remove. Add a small amount of water after the cold, add 8 ml of hydrochloric acid (6.1), following Continue to heat until the white smoke exhausted, remove, after cooling the full amount into the 1000 ml volumetric flask, diluted with water volume to the mark, shake. this Solution per gram of selenium containing 100 micrograms. You can also purchase commercially available standard solutions. 6.23 Selenium standard use of the solution. ρ = 1.00 mg/L. Accurately remove 10.00 ml of selenium standard stock solution (6.22) to 1000 ml volumetric flask and dilute the volume with hydrochloric acid solution (6.13) To the mark, shake. If the use of commercially available standard solution, can also be directly prepared into the standard use of selenium liquid.7 instruments and equipment7.1 Spectrophotometer. A cuvette with an optical path length of 30 mm. 7.2 adjustable thermoelectric plate. heating power 0 ~ 2.4 kW, the temperature range of room temperature ~ 400 ℃. 7.3 Pear-shaped separatory funnel. 250 ml. 7.4 Erlenmeyer flask. 250 ml. 7.5 General laboratory equipment and equipment commonly used.8 samples8.1 Sample collection Samples were collected according to the relevant regulations of HJ/T 91. The vials are glass or polyethylene bottles, whisked with nitric acid (6.14) And rinse with tap water and experimental water in turn. Each batch of samples should be accompanied by at least one full program blank (with the same batch of experimental water Instead of the sample). 8.2 Preservation of samples After sampling, if not measured in time, should be in proportion (1000 ml of sample by adding 10 ml of nitric acid) by adding nitric acid (6.2), at 4 ℃ The following cold storage, 14 d to complete the analysis. 8.3 Preparation of sample Remove.200 ml of the mixed sample into a 250 ml Erlenmeyer flask (7.4) (depending on the amount of total selenium in the sample, Water diluted to.200 ml), heated to 15 ml on the hot plate (set the temperature of 130 ℃ ~ 150 ℃), remove the slightly cold, Add 5 ml of nitric acid - perchloric acid solution (6.15), continue to digest on the hot plate (set the temperature of 180 ℃ ~ 210 ℃), to the bottle Filled with white smoke, continue to heat until the white smoke gradually disappeared, remove the slightly cold, add 2.5 ml hydrochloric acid solution (6.12), continue Heating the heating plate (set the temperature of 180 ℃ ~ 210 ℃), to the white smoke exhausted, remove the cooling, add 5 ml of hydroxylamine hydrochloride solution (6.20), to be tested. Note. In the process of heating and concentrating, it is strictly forbidden. 8.4 Preparation of laboratory blank samples A laboratory blank sample was prepared in the same manner as in the preparation of the sample (8.3) using the same batch of experimental water instead of the sample. 8.5 Preparation of full program blank samples Samples of the same batch will be sent to the sampling site, with the same batch of experimental water into the vial, in accordance with the preservation of the sample (8.2) and the preparation of the sample (8.3).9 Analysis steps9.1 Drawing of calibration curves 9.1.1 preparation Remove 0.00 ml, 0.50 ml, 2.00 ml, 5.00 ml, 10.00 ml and 25.00 ml selenium standard solution (6.23) In a group of 250 ml Erlenmeyer flask (7.4), add water to.200 ml, the preparation of selenium concentration were 0.00 μg/L, 2.50 μg/L, 10.0 μg/L, 25.0 μg/L, 50.0 μg/L, 125 μg/L. According to the same procedure as the preparation of the sample (8.3) Digestion. 9.1.2 color development The digested standard series were transferred to a group of 250 ml pear-shaped separatory funnel (7.3), treated with 20 ml of ethylenediaminetetraacetic acid Disodium mixed test solution using liquid (6.19) fractional cleaning conical flask, lotion all transferred to the separatory funnel, this time the solution was pink color. The pH was adjusted to 1 to 3 with sodium hydroxide solution (6.16) or hydrochloric acid solution (6.12), the solution was pale orange, 5.0 ml 3,3'-diaminobenzidine tetrachloride solution (6.21), shake, keep away for 30 min. 9.1.3 Extraction The color solution (9.1.2) was adjusted to pH 7 to 10 with sodium hydroxide solution (6.16) or hydrochloric acid solution (6.12) So that the solution slightly red, add 10.0 ml of toluene (6.4), fully shaking, standing stratification, abandoned the water phase, organic phase to be measured. 9.1.4 Draw the calibration curve The absorbance was measured with toluene (6.4) as a reference at a wavelength of 420 nm with a 30 mm cuvette. To deduct the lab empty The absorbance of the white sample (8.4) corresponds to the total selenium content (μg) as the abscissa, after deducting the laboratory blank sample (8.4) Of the absorbance value for the vertical axis, the establishment of calibration curve. 9.2 Determination of sample The prepared sample (8.3) was subjected to color development according to the same procedure of coloring (9.1.2) and extraction (9.1.3) of the calibration curve The organic phase extracted and extracted was placed in a 30 mm cuvette and measured at a wavelength of 420 nm with toluene (6.4) as a reference Luminosity. 9.3 Determination of blank sample The laboratory blank sample (8.4) and the whole program blank sample (8.5) were measured according to the same procedure as the test (9.2) of the sample. 10 results are calculated and expressed 10.1 Result calculation The mass concentration of total selenium in the sample is calculated according to equation (1) Vb AAA 0 (1) Where. ρ - the mass concentration of total selenium in the sample, μg/L; A - the absorbance of the sample; A0 - absorbance of laboratory blank samples; A - the intercept of the calibration curve; B - the slope of the calibration curve; V - sample size, L. 10.2 results are shown When the result is less than 10 μg/L, the result is retained to one after the decimal point; when the result is greater than or equal to 10 μg/L, The result retains three significant digits. 11 precision and accuracy 11.1 precision 6 samples of the total selenium concentration of 8.7 μg/L, 11.2 μg/L and 17.4 μg/L uniform standard samples were measured in parallel test. The relative standard deviations in the laboratory were 3.5% ~ 7.1%, 4.3% ~ 7.1% and 3.3% ~ 7.5% respectively. The relative standard deviation between the laboratory The differences were 2.5%, 4.1% and 3.7%, respectively. The reproducibility r was 1.3 μg/L, 1.7 μg/L and 2.1 μg/L, respectively. Do not. 1.4 μg/L, 2.1 μg/L and 2.6 μg/L. 11.2 Accuracy The concentration of total selenium in the six laboratories was 8.7 μg/L ± 1.0 μg/L, 11.2 μg/L ± 1.1 μg/L and 17.4 μg/L ± 1.7 μg/L The standard samples were tested. The relative errors were -6.9% ~ 1.1%, - 4.5% ~ 4.5% and -6.9% ~ 4.6%, respectively; the relative error was the final Values were -1.9% ± 5.7%, - 1.4% ± 6.8% and -3.1% ± 8.1%, respectively. Standard drafting unit of domestic sewage, smelting wastewater and chemical wastewater were measured spiked, plus scalar were 3.76 μg/L, 9.30 μg/L and 7.00 μg/L. The recoveries were 88.8% ~ 112.2%, 87.0% ~ 114.0% and 88.0% ~ 109.1%, respectively. The final recoveries were 98.7% ± 20.3%, 100% ± 22.2% and 98.6% ± 15.5%, respectively. 12 quality assurance and quality control 12.1 Every 20 samples or samples per batch (less than 20 samples) should be at least one laboratory blank and the blank value should be lower than the square Method to determine the lower limit. Otherwise, the quality of the test water, the purity of the reagent, the cleanliness of the vessel and the performance of the instrument should be checked. 12.2 Every 20 samples or samples per batch (less than 20 samples) should be at least a full program blank and the blank value should be lower than the square Method to determine the lower limit. Otherwise, the cause should be identified until the sample can be determined after passing. 12.3 3,3'-diaminobenzidine tetrachloride reagent has a great effect on the experimental results, and the calibration curve should be drawn for each change. The number of relationships should be greater than or equal to 0.999. 12.4 each batch of samples measured at least 10% of the parallel sample, the number of samples less than 10, at least a parallel sample, The relative deviation of the measurement results should be less than 25%. 12.5 Each batch of samples at least 10% of the actual sample plus standard sample, the number of samples less than 10, at least a measure of the actual Sample plus standard sample, spike recovery rate should be 75% to 125% range. 13 Waste treatment The waste and waste generated in the experiment should be collected and kept in a closed container, labeled and labeled. Quality unit processing. ...... |
