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HJ 635-2012 English PDF

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HJ 635-2012: Soil. Determination of water-soluble and acid-soluble sulfate. Gravimetric method
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Basic data

Standard ID HJ 635-2012 (HJ635-2012)
Description (Translated English) Soil. Determination of water-soluble and acid-soluble sulfate. Gravimetric method
Sector / Industry Environmental Protection Industry Standard
Classification of Chinese Standard Z18
Classification of International Standard 13.080
Word Count Estimation 16,144
Quoted Standard HJ 168; HJ/T 166; ISO 11048
Adopted Standard ISO 11048-1995, MOD
Regulation (derived from) Department of Environmental Protection Notice No. 16 of 2012;
Issuing agency(ies) Ministry of Ecology and Environment
Summary This standard specifies the measurement of soil water-soluble and acid-soluble sulfate gravimetric method. This standard applies to dried soil water-soluble and acid-soluble sulfate determination.

HJ 635-2012: Soil. Determination of water-soluble and acid-soluble sulfate. Gravimetric method


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Soil.Determination of water-soluble and acid-soluble sulfate.Gravimetric method National Environmental Protection Standard of the People's Republic Determination of water soluble and acid soluble sulfate in soil Gravimetric method Soil-Determination of water-soluble and acid-soluble sulfate -Gravimetric method Published on.2012-02-29 2012-06-01 Implementation Ministry of Environmental Protection released

Content

Preface II Warning..1 1 Scope 1 2 Normative references 1 3 Terms and Definitions..1 4 Principle of the method 1 5 interference and elimination..1 6 reagents and materials..2 7 instruments and equipment..3 8 samples..3 9 Analysis step 4 10 Results calculation and representation 5 11 Precision and Accuracy 5 12 Quality Assurance and Quality Control.5 13 Waste treatment 6 14 Notes 6 Appendix A (informative) This standard is in accordance with the chapter numbering of ISO 11048-1995 (E).7 Appendix B (informative) The technical differences between this standard and ISO 11048-1995(E) and their causes.9 Interlaboratory verification results of Appendix 110 (informative) ISO 11048 10

Foreword

To implement the "Environmental Protection Law of the People's Republic of China", protect the environment, protect human health, and regulate water solubility in soil This standard is established for the determination of acid-soluble sulfates. This standard specifies the gravimetric method for determining water soluble and acid soluble sulfates in soil. The technical content of this standard is to modify the method for determination of water-soluble and acid-soluble sulfate in soil quality. (ISO 11048-1995). Appendix A gives a list of the comparison of this standard with the ISO 11048-1995 chapter number, Appendix B The technical differences between this standard and ISO 11048-1995 and their reasons are given. This standard is the first release. Appendix A to Appendix C of this standard are informative annexes. This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection. This standard is mainly drafted by. Anshan Environmental Monitoring Center Station. This standard was approved by the Ministry of Environmental Protection on February 29,.2012. This standard has been implemented since June 1,.2012. This standard is explained by the Ministry of Environmental Protection. Soil water-soluble and acid-soluble sulfates Warning. Contaminated soil samples will produce toxic gases during acidification and heating, and the sample should be ventilated during operation. Carry out in the cabinet and take appropriate protective measures.

1 Scope of application

This standard specifies the gravimetric method for determining water soluble and acid soluble sulfates in soil. This standard applies to the determination of water-soluble and acid-soluble sulfate in air-dried soil. The water-soluble sulfate is determined. When the sample amount is 10.0 g and extracted with 50 ml of water, the detection limit of the method is 50.0. Mg/kg, the measurement range is.200~5.00×103 mg/kg; when the sample volume is 50.0 g, it is extracted with 100 ml water. The detection limit of the method is 20.0 mg/kg, and the measurement range is 80.0~1.00×103 mg/kg. Determination of acid-soluble sulfate, when the amount of sample For 2.0 g, the detection limit of this method is 500 mg/kg, and the measurement range is 2.00×103~2.50×104 mg/kg.

2 Normative references

The contents of this standard refer to the terms in the following documents. For undated references, the valid version applies to This standard. HJ 168 Technical Guidelines for Standardization and Revision of Environmental Monitoring and Analysis Methods HJ/T 166 Technical Specifications for Soil Environmental Monitoring ISO 11048 Soil quality - Determination of water-soluble and acid-soluble sulphates ( Soil quality-Determination of water-soluble and acid-soluble sulfate)

3 Terms and definitions

The following terms and definitions apply to this standard. 3.1 water-soluble sulfate It means that the soil can be extracted by deionized water of 1.2 and 1.5 (soil-to-water ratio m/V) under the conditions stipulated in this standard. Take the sulfate. 3.2 acid-soluble sulfate acid-soluble sulfate It refers to 6 mol/L dilute hydrochloric acid which can be 1.50 (diluted hydrochloric acid ratio m/V) in the soil under the conditions specified in this standard. The extracted sulfate.

4 Principle of the method

The sulfate in the soil is extracted with deionized water or dilute hydrochloric acid, and the extract is filtered through a slow quantitative filter paper, and then cerium chloride is added. The solution, the sulfate ion in the extract is converted to barium sulfate precipitate. The precipitate is filtered, dried, and constant weight. The mass of the lake is used to calculate the content of water soluble and acid soluble sulfate in the soil.

5 interference and elimination

5.1 When the concentration of nitrate, phosphate and silica in the extract is greater than 100 mg/L, 10 mg/L and 2.5 mg/L, respectively Positive interference; chromate, ferric ion and calcium ion concentrations greater than 10 mg/L, 50 mg/L and 100 mg/L, respectively Negative interference occurs. Interference can be eliminated by appropriately diluting the extract so that the concentration of the interferent is below the controlled concentration. 5.2 Sulfide in the sample will cause positive interference with the determination of acid soluble sulfate. Elimination method. take 20 ml hydrochloric acid solution (6.9) Heat to boiling in a 500 ml beaker. Stop heating and add 2 g of prepared soil sample with stirring. Continue the acid extraction operation. 5.3 The organic content in the extract is too high (ie, the permanganate index >30 mg/L) may be due to the adsorption of coprecipitation And interference measurement. Elimination method. Move a certain volume of the sample to the platinum evaporating dish and add 2 drops of methyl orange solution (6.12). Neutralize to pH 5~8 with hydrochloric acid solution (6.9) or sodium hydroxide solution (6.11), then add 2.0 ml hydrochloric acid solution (6.9). The evaporating dish was placed in a water bath and evaporated to near dryness, then 5 drops of sodium chloride solution (6.8) were added and evaporated to dryness. Move the evaporating dish to the muffle In the furnace, heat at 700 ° C for 15 min until the evaporating dish is completely red hot and the inner melt is ash. Cool the evaporating dish and use 10 ml Water wet ash, add 5 drops of hydrochloric acid solution (6.9), put it in boiling water bath and evaporate slowly, then slowly cool, then add 10 ml After the water was all transferred to a 500 ml beaker, to be tested.

6 reagents and materials

Unless otherwise stated, analytically pure reagents that meet national standards are used for analysis, and experimental water has a conductivity of less than 0.2. Deionized water at mS/m (measured at 25 ° C). 6.1 Concentrated hydrochloric acid. ρ (HCl) = 1.12 g/ml. 6.2 Ethanol. φ(CH3CH2OH) = 95%. 6.3 Ammonia. ρ(NH3•H2O) = 0.88 g/ml. 6.4 Nitric acid. ρ(HNO 3) = 1.39 g/ml. 6.5 anhydrous sodium carbonate (Na2CO3). 6.6 Disodium edetate (Na2EDTA•2H2O). 6.7 Ethanolamine (NH2CH2CH2OH). 6.8 Sodium chloride solution. ρ(NaCl)=100 g/L Weigh 10 g of sodium chloride dissolved in water and dilute to 100 ml. 6.9 Hydrochloric acid solution. c (HCl) = 6 mol/L Measure 500 ml of concentrated hydrochloric acid (6.1) dissolved in water and dilute to 1 L. 6.10 Barium chloride solution. ρ(BaCl2)=100 g/L Weigh 100 g of barium chloride (BaCl2•2H2O) dissolved in about 800 ml of water, heat and dissolve if necessary, and dilute after cooling. To 1 L. 6.11 sodium hydroxide solution. c (NaOH) = 5 mol/L Weigh.200 g of sodium hydroxide in 1000 ml of water. Store in polyethylene bottles. 6.12 methyl orange solution. ρ =1 g/L Weigh about 0.1 g of methyl orange dissolved in 50 ml of water, heat and dissolve, and then dilute to 100 ml after cooling. Glass drop bottle Save. 6.13 Silver nitrate solution. c(AgNO3)=0.1 mol/L Weigh 17 g of silver nitrate in about 800 ml of water and dilute to 1 L. Keep the brown bottle in the dark. 6.14 Ammonia solution. 1 1. 6.15 坩埚 lotion Weigh 5 g of ethylenediaminetetraacetic acid disodium salt (6.6), and weigh 25 ml of ethanolamine (6.7) dissolved in 1 L of water. 6.16 Quantitative filter paper. slow speed, Ф 12.5cm. 6.17 Red litmus paper.

7 Instruments and equipment

7.1 Pre-treatment tools for soil. wooden hammer, soil grinder, mortar, sample sieve (2 mm, 0.25 mm), etc. 7.2 Glass container. A ground glass container capable of holding 10 g, 50 g and.200 g of soil. 7.3 Balance. The accuracy is 0.1g and 0.0001 g respectively. 7.4 Oscillator. The oscillation frequency can reach 360 r/min. 7.5 Vacuum suction device. vacuum pump, buffer bottle, 500 ml receiving bottle, etc. 7.6 Constant temperature oven. 7.7 Dryer. Anhydrous discolored silica gel. 7.8 Polyethylene bottle with lid. 250 ml. 7.9 Porcelain funnel (Brinell funnel). 100 mm in diameter. 7.10 with a colorimetric tube. 10 ml. 7.11 Glass core funnel (glass sintered crucible). volume 30 ml and G4 aperture. Washing solution before use (6.15) Soak overnight, wash with water repeatedly with suction. Dry to constant weight before use. Constant weight method. drying at 105±2°C for 1h and Cool in the dryer and accurately weigh. Repeat drying, drying for 10 minutes each time, cooling to room temperature in the dryer until the two times The near mass difference was within 0.0002 g and the final mass of the glass core funnel was recorded. 7.12 Platinum Evaporating Dish. 250ml. 7.13 Thermostat. 7.14 Muffle furnace. The temperature can reach 900 °C. 7.15 Water bath. The temperature can reach 100 °C. 7.16 Instruments and equipment commonly used in general laboratories.

8 samples

8.1 Sample collection and preservation Soil samples were collected and stored in accordance with the relevant regulations of HJ/T 166. 8.2 Preparation of samples The air-dried sample was passed through a 2 mm sieve, and a sample of about.200 g was obtained by distilling the soil sample by a quarter method. Over 0.25mm sieve, Further shrinking about 50g (for the determination of 1.2 soil water than water-soluble sulfate) or about 10g (for 1.5 soil water than water) A sample of a soluble sulfate and an acid-soluble sulfate. Place the sample in a suitable container at no more than 40 ° C Dry until the sample is weighed less than 0.1% (m/m) every 4 h and cooled in a desiccator. Note 1. If the material left by the 2mm sieve cut contains gypsum block, it should be manually cut out, crushed and passed through a 2mm sieve and merged into the sieved sieve. Note 2. Other shrinkage methods can be used to narrow the soil sample. 8.3 Preparation of samples 8.3.1 Extraction of water-soluble sulfates in a 1.5 ratio of soil to water Weigh 10.0g sample (8.2) in a 250ml polyethylene bottle, add 50.0ml water, tighten the cap and place it in the shaker On the top, extract at 16~25 °C for 150h at 150~200 r/min. Use a slow quantitative filter paper to filter on a Buchner funnel The liquid was taken to a 500 ml receiving bottle and transferred to a 50 ml colorimetric tube. The volume of the extract was recorded and tested. 8.3.2 Extraction of water-soluble sulfates in a 1.2 ratio of soil to water Weigh 50.0g sample (8.2) in a 250ml polyethylene bottle, add 100.0ml water, tighten the cap and place it on the oscillator Above, oscillate at 150~200 r/min at 20~25°C for 16h. Filter on a Buchner funnel using slow quantitative filter paper Transfer the extract to a 500 ml receiving vial, transfer to a 100 ml colorimetric tube, and record the volume of the extract for testing. 8.3.3 Extraction of acid-soluble sulfate Weigh 2.0 g of sample (8.2) into a 500 ml beaker and slowly add 100.0 ml of hydrochloric acid solution (6.9). On the beaker Cover the watch glass, heat it to boiling in a fume hood, and boil for 15 minutes on low heat. Then rinse the inside of the watch glass with a proper amount of water, Add a few drops of nitric acid (6.4) in a boiling state. Slowly add aqueous ammonia solution (6.14) with a pipette while stirring until it appears The reddish brown oxide precipitates and the red litmus paper (6.17) turns blue. Filter on a Buchner funnel using slow quantitative filter paper Extract the extract into a 500ml receiving bottle and wash the filter paper with water until the filtrate has no chloride ions (ie add a drop of filtrate to hold a small amount of nitrate) The silver tube (6.13) colorimetric tube solution showed no precipitation). Collect all the filtrate, measure the volume with a measuring cylinder, and record the extract. volume. Transfer the extract to a 500 ml glass or plastic reagent bottle for testing. Note 3. During the addition of hydrochloric acid solution, ensure that there is no spillage. Note 4. When adding ammonia and acid, a large amount of flocculated oxide precipitates, and some sulfates may be wrapped in it and cannot be washed out. In this case, a secondary precipitation is recommended. Namely. carefully put the filter paper with sediment on the original beaker, add at least 20ml hydrochloric acid solution (6.9) Stir until the reddish brown oxide precipitate dissolves, heat and filter according to step 8.3.3, and combine the filtrate with the 8.3.3 extract. Note 5. The volume of all extracts collected should not exceed.200 ml. If the filtered extract cannot be measured in time, it should be stored in a glass bottle or a polyethylene bottle and stored at 2~5 °C. No more than 1 week between. The vial should be completely insulated from air to prevent oxidation of sulfides and sulfites. 8.4 Preparation of Blank Samples Without adding a sample, a blank sample was prepared in accordance with the same procedure as in 8.3.

9 Analysis steps

9.1 Acidizing and boiling Pipette 10~200ml of appropriate sample (8.3) in a 500ml beaker. The sulfate ion content in the sample should not exceed 50mg. Record the exact volume of the sample and dilute to.200 ml with water. Add 2~3 drops of methyl orange solution (6.12) with hydrochloric acid Solution (6.9) or sodium hydroxide solution (6.11) to pH 5~8, then add 2.0ml hydrochloric acid solution (6.9), boil At least 5 minutes. If the solution is clear after boiling, proceed to step 9.2. If insoluble matter occurs, use a slow quantitative filter paper to filter The mixture was rinsed with a small amount of hot water, and the filtrate and washings were combined in a 500 ml beaker, and the 9.2 procedure was continued. Note 6. If it is suspected that the precipitate in the insoluble matter of the filtration contains soluble sulfate, it can be operated as described in Note 14.1. 9.2 Precipitation Slowly add 5~15ml cesium chloride solution (6.10) at about 80 °C to the above boiled solution with a pipette, and then heat the solution. The solution was allowed to stand for at least 1 h, and after cooling, it was placed in a 50 ± 10 ° C incubator for precipitation overnight. 9.3 Filtering Place a constant weight glass sand core funnel on the suction filter bottle, carefully filter the precipitate by suction, and stir with the glass rod of the rubber sleeve. The precipitate in the beaker is washed repeatedly with deionized water, and all the washing liquid is incorporated into the glass core funnel to rinse the sand core. The precipitate of the bucket is free of chloride ions. Note 7. The final three times can be used to rinse the sediment in the sand core funnel with 5ml ethanol (6.2) to shorten the drying time. Determination of chloride ion in the filtrate. Add 5 ml of silver nitrate solution (6.13) to a 10 ml colorimetric tube, and add suction filtration. 5 ml of filtered sputum in the bottle. If no turbidity is produced, it is believed that there is no chloride ion in the precipitate, otherwise the precipitation should continue to be washed. 9.4 Drying Remove the glass sand core funnel, dry the constant weight according to the procedure of 7.11, and record the quality of the last glass sand core funnel. 9.5 Blank test Remove the blank sample (8.4) with the same volume as the sample, and measure the sulfate in the blank sample according to steps 9.1 to 9.4. content. The difference in mass between the glass core funnel and the suction weight after drying and filtration was calculated. 10 Calculation and representation of results 10.1 Calculation of results The content of water-soluble or acid-soluble sulfate in the sample ω (mg/kg) was calculated according to the formula (1). As Vm Vmm ×××−= 012 104116.0m- )(ω (1) In the formula. ω - the content of water-soluble or acid-soluble sulfate in the sample, mg/kg; M0--the quality of the precipitate in the blank sample, g; M2--filtering the quality of the glass sand core funnel after precipitation, g; M1--the mass of the glass core funnel before the determination of the sample, g; VA--the volume of the sample, ml; VE--the total volume of the extract, ml; mS--sample amount, g; 0.4116 - mass conversion factor (sulfate/barium sulfate). 10.2 Results are expressed The calculation result retains three significant digits. 11 Precision and accuracy 11.1 Precision The results of ISO interlaboratory verification are detailed in Appendix C. 11.2 Accuracy Six times of parallel determination of the spiked sample in the laboratory, water-soluble method. when the spiked amount is 5.0~40.0 mg, the standard is added. The recovery rate is 94.1~100%; acid-dissolving method. when the standard addition amount is 4.0~10.0 mg, the recoveries of standard addition are 91.0%~118%. 12 Quality Assurance and Quality Control 12.1 Blank experiment At least one blank test should be determined for each batch of samples, and the blank value should be deducted from the sample measurement results. If the blank value is higher than At 0.0010g, a re-measurement should be performed. 12.2 Determination of parallel samples 10% of parallel samples should be determined for each batch of samples, and at least one parallel sample should be determined for less than 10 samples. Parallel sample The relative deviation of the fruit should be within 20%. 12.3 Determination of spiked recovery of samples Each batch of samples should be tested with 10% of the spiked samples. The actual sample spike recovery should be between 80% and 120%. 13 Waste treatment 13.1 The standard sample solution of this experiment shall be kept in a safe place and shall not be discarded at will. 13.2 The waste liquid produced in this experiment should be stored in a centralized manner and entrusted to the relevant units for processing. 14 Precautions 14.1 Determination of Sulfate in Insolubles If it is suspected that the insoluble matter (9.1) in the filter paper may contain soluble sulfate, the following steps should be taken. Put the precipitate and filter paper in step 9.1 into the platinum evaporating dish, put it into the muffle furnace at room temperature, and raise it to 500 ° C ashing filter paper, ash The crucible was mixed with 4 g ± 0.1 g of anhydrous sodium carbonate (6.5), heated to 900 ° C to melt, held for 15 min, and cooled to room temperature. Then, 50 ml of water was added to the evaporating dish to heat and dissolve the melt, and the mixture was filtered through a slow quantitative filter paper. Rinse with 20ml of water The paper, the combined filtrate and the washing solution were measured according to the steps 9.1 to 9.4. The sulfate in the insoluble matter is measured and added to the soil. In the measurement results of the soil extract, the total content of the soluble sulfate was calculated. 14.2 If the sulfate content in the actual sample exceeds the upper limit of the measurement, the amount of the extract solution may be appropriately reduced.

Appendix A

(informative appendix) This standard is in contrast to the chapter number of ISO 11048-1995(E) Schedule A.1 gives a checklist of the numbering of this standard and ISO 11048-1995(E). Schedule A.1 This standard is in contrast to the chapter numbering of ISO 11048-1995(E) The international standard chapter number corresponding to the standard chapter number 1 1.1, 1.4 - 1.1 2 1.2 3 - 4 1.1, 1.3, 6.2 - 1.3 - 1.4 - 2.1 - 2.2 5.1 6.8 and Table 3 5.2 5.2.4 5.3 6.8, 6.9.1 6 3.2.1.1, 4.2.1.1, 5.2.1, 6.3, 6.10.1 7.1~7.10, 7.12~7.16 2.3.1, 2.4.1, 3.2.2, 4.2.2, 5.2.2, 6.4 7.11 6.4.1, 6.10.1, 6.6.5 8.1 1.1 8.2 2.3.2, 2.4.2, 3.2.3, 4.2.3, 5.2.3 8.2 Note 1, Note 2 2.3.2 Note 1, Note 2 8.2 Note 1, Note 2 2.4.2 Note 3, Note 4 - 3.1, note 5 8.3.1 3.2.4 - 3.3 - 4.1 8.3.2 4.2.4 - Note 6 - 4.3 - 5.1, note 7 8.3.3 5.2.4, 6.5 Note 3 5.2.4(b) Warning note 8 - Note 9 Note 4 Note 11 Note 5 5.2.4 - 5.3 The international standard chapter number corresponding to the standard chapter number 8.4 - - 6.1 9.1 6.6.1, 6.6.2 Note 6 Note 15 9.2 6.6.3 9.3 6.6.4 9.4 6.6.5 9.5 6.6.6 10 6.7 11 - 12 - 13 - - 6.8 14.1 6.9.2 14.2 - - 7.1 - 7.2 Appendix A - Appendix B - Appendix C Appendix A

Appendix B

(informative appendix) Technical differences between this standard and ISO 11048-1995(E) and their causes Table B.1 gives a list of the technical differences between this standard and ISO 11048-1995(E) and their causes. Schedule B.1 Technical differences between this standard and ISO 11048-1995(E) and their causes Reasons for technical differences in the provisions of this standard Deleted the original standard 1.4 scope of application and the detection limit Narrative content. Related content is described in the scope of application. 3 Added terms and definitions. In order to facilitate the understanding of standard technical content, this clause has been added. 8.1 Revised reference standards for soil sample collection and storage. Try to connect with relevant domestic technical specifications. Increased accuracy data, ie, in-lab verification numbers according to. In accordance with HJ 168 regulations, supplements in the laboratory Relevant test content, determined the method Exact. 12 Added quality assurance and quality control provisions. In accordance with HJ 168 regulations, add these terms. 13 Added waste disposal provisions. In accordance with HJ 168 regulations, in order to prevent pollution caused by experiments, increase the provisions. 14.2 Added considerations related content. This requirement has been added to meet the monitoring needs of different levels of samples. - The determination of the dry weight of substances 2.2, 3.3, 4.3, 5.3 was deleted. Cleared the test during the preparation of the sample The dried sample is fixed. Appendix A adds a comparison table between this standard and ISO 11048-1995 (E). In accordance with the requirements of international standards Add related content. Appendix B adds technical differences between this standard and ISO 11048-1995(E) and their causes. In accordance with the requirements of international standards Add related content.

Appendix C

(informative appendix) Interlaboratory verification results for ISO 11048 Acid-soluble and water-soluble sulfate content of 4 soil samples and sulfuric acid in 1 part of the solution were determined in 11 laboratories. Salt content. For the source of 4 soil samples, see Appendix C.1. Interlaboratory repeatability (r) and reproducibility of 1 solution. (R), see attached table C.2; interlaboratory repeatability (r) and reproducibility (R) of 4 soil samples, see attached table C.3, attached Table C.4 and Schedule C.5. Schedule C.1 Soil properties for interlaboratory testing Soil sample description Natural soil with added gypsum (C) - limited dissolved gypsum-regulated water-soluble sulfate Natural soil with sodium sulfate added (C)--high water-soluble sulfate Natural soil Soil/filled soil from industrial contaminated land Schedule C.2 Interlaboratory test results for sulfate testing of test solutions Number of labs after eliminating suspicious values Suspicious value (number of laboratories) Acceptable value Average, mg/L Repeatability standard deviation sr, mg/L Repeatability coefficient of variation VCr, % Repeatability limit (R=2.8×sr) Reproducibility standard deviation sR, mg/L Reproducibility coefficient of variation VCR, % Reproducibility limit (R=2.8×sR) 1.11 5.20 Schedule C.3 Interlaboratory test results for acid-soluble sulfate testing of test soils Soil ABCD Number of labs after eliminating suspicious values Suspicious value (number of laboratories) Adopted value Average, % of air dried soil Repeatability standard deviation sr, % of air-dried soil Repeatability coefficient of variation VCr, % Repe...

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