HJ 659-2013Water quality. Determination of cyanide and others by vaccum testing tube-electric colorimeter (English PDF)

Foreword

To implement the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on Water Pollution Prevention and Control, to protect the environment, this standard is formulated to ensure human health, standardize China's water environment monitoring methods, and meet the needs of water quality emergency monitoring work.

This standard specifies the determination of cyanide, fluoride, sulfide, divalent manganese, hexavalent chromium, nickel, ammonia nitrogen, aniline, Vacuum test tube method for contaminants such as nitrate nitrogen, nitrite nitrogen, phosphate and chemical oxygen demand.

This standard is the first release.

Appendix A of this standard is a normative appendix, Appendix B and Appendix C are informative appendices.

This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection.

This standard is mainly drafted by. Henan Environmental Monitoring Center.

This standard was approved by the Ministry of Environmental Protection on September 18, 2013.

This standard has been implemented since September 20, 2013.

This standard is explained by the Ministry of Environmental Protection.

Determination of water quality cyanide, etc. Vacuum test tube - electronic colorimetry

1 Scope of application

This standard specifies the determination of cyanide, fluoride, sulfide, divalent manganese, hexavalent chromium, nickel, ammonia nitrogen, aniline, Vacuum test tube method for contaminants such as nitrate nitrogen, nitrite nitrogen, phosphate and chemical oxygen demand.

This standard applies to cyanide, fluoride, sulfide, bivalent in groundwater, surface water, domestic sewage and industrial wastewater.

Manganese, hexavalent chromium, nickel, ammonia nitrogen, aniline, nitrate nitrogen, nitrite nitrogen, phosphate, and chemical oxygen demand Quick analysis. Other pollutants may also be applied to this standard if they pass the verification. The verification method is shown in the informative Appendix C.

The method detection limits for the target are shown in Table 1.

Table 1 Detection limit of this method

No. Compound name detection limit (mg/L) No. Compound name detection limit (mg/L)

1 Cyanide 0.0099 Nitrite (N) 0.03

2 Fluoride 0.5 8 Divalent manganese 0.5

3 Sulfide 0.1 9 Hexavalent Chromium 0.1 4 ammonia nitrogen 0.2 10 nickel 0.2 5 phosphate 0.05 11 aniline 0.1

6 Nitrate (N) 0.7 12 CODCr 10

2 Normative references the contents of this standard refer to the following documents or their terms. For undated references, the valid version is appropriate.

Used in this standard.

HJ 589 Technical Specifications for Emergency Monitoring of Environmental Emergencies HJ/T 91 Surface Water and Wastewater Monitoring Technical Specifications HJ/T 164 Technical Specifications for Groundwater Environmental Monitoring

3 Terms and definitions the following terms and definitions apply to this standard.

3.1 vacuum test tube vacuum test tube Made of borosilicate glass or quartz glass, with a certain degree of vacuum, built-in test reagents, automatic quantitative absorption after breaking A test tube that is subjected to a chemical color reaction with a specific reagent to be tested.

3.2 electronic colorimeter electric colorimeter the electronic colorimeter consists of a light source, a chrominance sensor, a colorimetric cell, a signal simulation system, and a display.

The chrominance sensor is a signal receiver that determines the chromaticity signal of the color of the colored compound generated by a specific chemical color reaction.

A quantity of analytical electronic instruments.

4 Principle of the method the vacuum glass detecting tube sealed with the reaction reagent is broken in the water sample, and the sample is automatically metered into the tube, and the sample is in the sample.

The analyte and the reagent react rapidly and quantitatively to form a colored compound, and the color value thereof is proportional to the content of the analyte. Chemically the functional relationship between the chrominance signal of the color reaction and the concentration of the analyte is stored in an electronic colorimeter, and the water is directly read after the measurement.

The content of the analyte in the sample.

See Appendix A for the principle of determination of each type of pollutant.

5 interference and elimination

5.1 Suspended matter or algae in water may interfere with the measurement, and interference can be eliminated by filtration or precipitation;

In the case of the case, the interference can also be eliminated by dilution.

5.2 Determine whether the chromaticity causes interference by the result of the standard recovery test. When the color of the water sample interferes with the measurement, it is determined Interference can be eliminated by dilution if the range allows.

5.3 See Appendix A for other interference and elimination methods.

6 reagents and materials Unless otherwise stated, analytically pure reagents that meet national standards were used for the analysis. Experimental water is used without target dry Disturbed distilled or deionized water.

6.1 Special additives. solid or liquid reagents. Used to assist color reaction or eliminate interference, configuration method reference test tube use Instructions.

7 Instruments and equipment

7.1 Electronic colorimeter. LED or xenon lamp source, power-on stabilization time <= 10 seconds, sensor three primary color wavelength range. red.

580-750nm; green. 500-600nm; blue. 410-510nm; built-in working curve; power supply. 220v AC power supply, No. 5, 7th battery or dedicated power adapter; adapt to environmental conditions. temperature 0-40 ° C, maximum relative humidity 90% RH.

7.2 Vacuum test tube. high borosilicate or quartz glass material, vacuum. -100 ~ -80KPa, sealed a certain amount of reagents. shape Uniform, should be stored at normal temperature, low temperature or dark place according to the instructions during the warranty period.

7.3 Heating device. use 12v DC or 220v AC power supply, the temperature is set to 50-150 °C continuously adjustable, temperature precision Degree ± 0.5 ° C, suitable for test tube heating design.

7.4 Common instruments and equipment used in general laboratories.

8 Samples

9 Analysis steps

10 Calculation and representation of results

The results were read directly by an electronic colorimeter in mg/L. The effective number is retained to the lower limit of quantitation, chemical needs the amount of oxygen is taken as an integer.

11 Precision and accuracy

12 Quality Assurance and Quality Control

12.1 Check the instrument and test tube regularly according to the requirements of the instrument manual. If the instrument manual does not stipulate, at least half a year.

Check once.

Instrument and test tube accuracy check method. configure the calibration solution of 0.1C, 0.5C and 0.9C concentration, when measuring the knot If the relative error is greater than 20%, the instrument and the test tube should be sent back to the manufacturer for inspection at the same time.

Calibration or void detection tube for the quantitative curve.

Note. C in 0.1C, 0.5C, and 0.9C refers to the highest concentration value of the instrument's quantitative curve.

12.2 Each batch of samples should be synchronized to make a full program blank, the measurement result should be lower than the method detection limit, otherwise the vacuum test should be checked.

tube.

12.3 Each sample shall be tested as a pair of parallel samples with a relative deviation of less than 20%.

12.4 Each batch of samples shall be simultaneously tested in parallel with a certified reference material or standard sample to verify the accuracy.

The relative error should be less than 25%.

12.5 Each sample should be synchronized to a standard sample with a spiked amount of 0.5C, and the recovery rate should be 70% to 130%.

The limit data measurement result is invalid.

12.6 When the results are reported, the quality control data of the same batch analysis should be given at the same time, indicating the method detection limit.

13 Precautions

13.1 Test tubes and special additives should be stored under specified conditions and used during the warranty period.

13.2 Select the appropriate test tube according to the purpose of the test and the condition of the water sample.

13.3 When using the glass test tube, care should be taken to protect the eyes and face from splashing of the additive or scratching of the glass.

14 Waste treatment

The used test tubes are safely disposed of in laboratory waste.

Appendix A

(normative appendix) First, the principle of the method, interference and elimination, and precautions A.1 Cyanide A.1.1 Principle of the method Cyanide (CN-) and organic ketone test solution are heated in the presence of sodium carbonate, and yellow to deep red is formed by ion association reaction.

The color complex has a linear relationship between the color value of the colored complex and the concentration of cyanide.

A.1.2 Interference and elimination

a) S2- <= 30mg/L, acetone <= 5000mg/L does not interfere;

b) NH3-N<=30mg/L does not interfere, and >30mg/L is negative interference.

A.1.3 pH and reaction time the water sample to be tested should be controlled to have a pH of >= 4, and the reaction time of heating at 50 ° C for 10 minutes.

A.1.4 Precautions

a) The time during which the test tube is placed in the heated reactor shall be strictly consistent with the specified time, otherwise the reading may be in error;

b) If the test tube inhales the sample and begins to show a color reaction without heating, indicating that the cyanide concentration in the sample is too high, it should be diluted after appropriate dilution.

A.2 Fluoride

A.2.1 Principle of the method Fluoride (F-) and hydroxy hydrazine test solution react in the presence of hydrazine to form a blue to rose red colored complex, colored network the chroma value of the compound has a linear relationship with the concentration of fluoride.

A.2.2 Interference and elimination

a) Cl-<=1000mg/L, NO2 -<=100mg/L, Ca2 <=80mg/L, SO42-<=300mg/L, NO3-<=150mg/L Does not interfere with the determination;

b) Cu2, Cr6, Pb2 >3.0mg/L, Mn2 >2.0mg/L, Ni2, Hg2 >5.0mg/L, PO43 >30mg/L There is interference, and the interference can be removed by distillation.

A.2.3 pH and reaction time the pH of the water sample to be tested should be controlled at <= 8. The reaction time is 2 to 3 minutes.

A.2.4 Precautions

The amount of special fluorine auxiliary added has a great influence on the color tone of the display. The sample volume and special fluorine assist should be strictly controlled according to the instructions.

The amount of agent added.

A.3 Sulfide

A.3.1 Principle of the method Sulfide reacts with N,N-dimethyl-p-phenylenediamine and high-iron under acidic conditions to form a methylene blue colored complex.

The color value of the colored complex has a linear relationship with the concentration of the sulfide.

A.3.2 Interference and elimination

a) SO32-, S2O32-<=20mg/L, NO2-<=15mg/L, CN-7.5 mg/L;

b) Ca2 and Mg2 <=1,000mg/L, and Ni2 and Cr6 <=50mg/L do not interfere;

A.5.3 pH and reaction time when accurately heated at 25±1°C for 10 minutes, it should be tested quickly after removal, and no pH adjustment is required before the reaction.

A.5.4 Precautions

a) The reaction temperature is >=30 °C, there is positive interference to the determination of nitrite nitrogen, and should be controlled below 30 °C;

b) After the test tube draws the water sample to be tested, it should be shaken and placed in the dark in the dark to avoid direct sunlight, otherwise the color tone will be A change in reading causes a reading error.

A.6 Divalent manganese A.6.1 Principle of the method Divalent manganese is oxidized by periodate to red permanganate in the presence of acidic conditions and pyrophosphate, the red combination the chromaticity value of the substance has a linear relationship with the concentration of divalent manganese.

A.6.2 Interference and elimination

a) NO2-, SO42-, Cl-<=300mg/L, PO43-, NO3-<=100mg/L without interference;

b) Fe3, Cu2 <= 10mg/L, Ni2 <= 50mg/L, Cr6 <= 6.0mg/L does not interfere;

c) The reducing agent such as SO32- interferes with the reaction, and can be removed by adding nitric acid and sulfuric acid by heating and digesting.

A.6.3 pH and reaction time the pH of the water sample to be tested should be controlled at 3.0 to 5.0 and the reaction time should be 1 to 5 minutes.

A.7 hexavalent chromium A.7.1 Principle of the method the hexavalent chromium and diphenylcarbonyl hydrazide test solution simultaneously undergo redox and complexation reactions under appropriate pH conditions to generate the reddish purple complex has a linear relationship between the color value of the colored complex and the concentration of hexavalent chromium.

A.7.2 Interference and elimination

a) Hg2 <= 20mg/L, Cu2 <= 25mg/L does not interfere;

b) When the hexavalent chromium content in the water sample is >=20mg/L, the display color will decrease, and the appropriate multiple should be diluted before testing.

A.7.3 pH and reaction time the reaction is carried out at room temperature for 3 to 4 minutes, and the pH is not required to be adjusted before the reaction.

A.7.3 Precautions

To determine if the hexavalent chromium concentration in the water sample is too high, it can be tested by quantitative dilution. If diluted test results If the quantitative results are not proportional to the direct test results, it can be determined that the former hexavalent chromium concentration is too high.

A.8 Nickel ion

A.8.1 Principle of the method in an ammonia solution with iodine, nickel reacts with diacetyl ketone to form a red compound, and the chromaticity value of the red compound it has a linear relationship with the concentration of nickel ions.

A.8.2 Interference and elimination

a) Hg2 <=5.0mg/L, Co2 <=3.0mg/L does not interfere; Cu2, Fe3, Pb2, Cr6, Al3, CN-<=8.0mg/L Do not interfere with;

b) Mn2+>=1.0mg/L interferes with this reaction and should be removed beforehand.

A.8.3 pH and reaction time the reaction time should be between 1 and 5 minutes, and the pH of the water sample should be controlled between 4 and 6.

A 8.4 Precautions

The amount of water sample and special additives must be accurate. The auxiliaries are tightly closed after use to prevent evaporation.

A.9 Ammonia nitrogen A.9.1 Principle of the method the ammonia nitrogen in the form of free ammonia or ammonium ions reacts with the Nessler reagent to form a yellow to yellow brown colored complex.

The chromaticity value of the complex has a linear relationship with the concentration of ammonia nitrogen.

A.9.2 Interference and elimination

a) The total amount of Ca2 and Mg2 is <=100mg/L, methanol, ethanol, NO3- <=100mg/L, and aniline <=10mg/L does not interfere;

b) S2-, Pb2, and formaldehyde have positive interference with this reaction, and acetone has negative interference, and appropriate pre-treatment is needed to eliminate interference.

Such as distillation or addition of zinc acetate to precipitate sulfides.

A.9.3 pH and reaction time the pH of the water sample to be tested should be controlled at >= 4 and the reaction time is 2 to 5 minutes.

A.9.4 Precautions

a) When the concentration of ammonia nitrogen is too high, turbidity will occur in the color development, which should be quantitatively diluted with distilled water before measurement.

b) If the water sample is complex, sometimes it will be suspended during the test. In this case, before the suspension appears or in suspension Quickly read when the object is just shaken;

A.10 Aniline

A.10.1 Principle of the method Aniline reacts with nitrite under acidic conditions to form diazonium salt, and diazonium salt undergoes coupling reaction with aniline to form red A chromatic dye having a linear relationship between the chromaticity value of the red dye and the concentration of aniline.

A.10.2 Interference and elimination Phenol content <= 100mg/L, methanol, ethanol, acetone <= 5000mg/L No interference to this reaction.

A.10.3 pH and reaction time the pH value of the water sample to be tested should be controlled at <=7; after adding the auxiliary agent, the reaction time should be strictly controlled within 2~3 minutes.

The test time should be strictly controlled for 10~12 minutes, otherwise the reading will be too high.

A.11 phosphate

A.11.1 Principle of the method in the presence of acidic conditions and cerium salts, orthophosphates react with amm...