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HJ 1049-2019Water quality--Determination of 4 nitrophenol compounds --Liquid chromatography-triple quadrupole mass spectrometry (English PDF)

水质 4 种硝基酚类化合物的测定液相色谱-三重四极杆质谱法

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Issued by

Ministry of Ecology and Environment

Level / Type

National · Mandatory

Issue date

January 1, 1970

Implementation date

April 24, 2020

Scope

HJ 1049-2019 is the English-translated version of 水质 4 种硝基酚类化合物的测定液相色谱-三重四极杆质谱法.

HJ 1049-2019 — This standard specifies liquid chromatography-triple quadrupole mass spectrometry for the determination of four nitrophenol compounds in water. This standard applies to 2,6-dinitrophenol, 2,4-dinitrophenol, Determination of 4 nitrophenols such as 4-nitrophenol and 2,4,6-trinitrophenol.

When the injection volume is 10 µl, the method detection limits of the four nitrophenol compounds are 0.4 µg/L ~ 0.6 µg/L. The lower limit is 1.6 µg/L to 2.4 µg/L. See Appendix A for details.

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Document preview — HJ 1049-2019

National Standard of the People's Republic of China

ICS: 13.060
Classification: Z 16

Issued by: Ministry of Ecology and Environment

Foreword
1 Scope
2 Normative references
3 Methodology
4 Interference and cancellation
5 Reagents and materials
6 Instruments and equipment
7 Sample
8 Analysis steps
9 Results calculation and representation
10 Precision and accuracy
11 Quality Assurance and Quality Control
12 Waste disposal
Appendix A (Normative) Method detection limit and determination limit
Appendix B (informative) Mass spectrometer reference conditions
Appendix C (informative) Precision and accuracy of the method

Foreword

In 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 Water Pollution Control", protect the ecology Environment, protect human health, standardize the determination method of nitrophenol compounds in water, and formulate this standard.

This standard specifies the liquid phase determination of 4 nitrophenol compounds in surface water, groundwater, domestic sewage and industrial wastewater.

Chromatography-Triple Quadrupole Mass Spectrometry.

Appendix A to this standard is a normative appendix, and appendixes B to C are informative appendixes.

This standard is issued for the first time.

This standard is formulated by the Department of Eco-Environmental Monitoring, Laws and Standards Department of the Ministry of Ecology and Environment.

This standard was drafted. Sichuan Ecological Environment Monitoring General Station.

Verification units of this standard. Chongqing Ecological Environment Monitoring Center, Guangyuan Environmental Monitoring Center Station, Panzhihua Environmental Monitoring Center Monitoring Center Station, Shengzhou Environmental Monitoring Center Station, Yibin Environmental Monitoring Center Station and Nanchong Environmental Monitoring Center Station.

This standard was approved by the Ministry of Ecology and Environment on October 24, 2019.

This standard will be implemented as of April 24, 2020.

This standard is explained by the Ministry of Ecology and Environment.

Determination of 4 nitrophenol compounds in water quality Liquid chromatography-triple quadrupole mass spectrometry Warning. The standard materials and organic solvents used in the experiment are toxic and hazardous substances, reagent preparation and sample preparation process it should be carried out in a fume hood; wear protective equipment as required to avoid contact with skin and clothing.

1 Scope

This standard specifies liquid chromatography-triple quadrupole mass spectrometry for the determination of four nitrophenol compounds in water.

This standard applies to 2,6-dinitrophenol, 2,4-dinitrophenol, Determination of 4 nitrophenols such as 4-nitrophenol and 2,4,6-trinitrophenol.

When the injection volume is 10 µl, the method detection limits of the four nitrophenol compounds are 0.4 µg/L ~ 0.6 µg/L.

The lower limit is 1.6 µg/L to 2.4 µg/L. See Appendix A for details.

2 Normative references

This standard refers to the following documents or clauses therein. For undated references, the valid version applies to this standard.

HJ/T 91 Technical specifications for surface water and sewage monitoring HJ/T 164 Technical Specifications for Groundwater Environmental Monitoring

3 Method principle

The samples were directly injected after filtration or purification, and were separated and detected by liquid chromatography-triple quadrupole mass spectrometry.

Qualitative analysis based on retention time and characteristic ions, quantification by internal standard method.

4 Interference and cancellation

4.1 When matrix interferences exist in the sample, you can optimize the chromatographic conditions, dilute the sample, reduce the injection volume, and Products are reduced or eliminated by pretreatment.

4.2 When there is interference of isomers in the sample, you can improve the resolution by changing the chromatographic conditions or choose a different the secondary mass ion eliminates interference.

4.3 When the interference of coexisting organics in the sample is determined, a part of the interference can be removed by extraction with a mixed solution of n-hexane-dichloromethane.

Take the water phase for analysis.

5 Reagents and materials

Unless otherwise stated, all analytical reagents that meet national standards are used for analysis.

Standard compound of pure water.

5.1 Methanol (CH3OH). pure by liquid chromatography.

5.2 Dichloromethane (CH2Cl2). pure liquid chromatography.

5.3 n-hexane (C6H14). pure by liquid chromatography.

5.4 Formic acid (HCOOH). pure liquid chromatography.

5.5 Ammonium formate (HCOONH4). pure liquid chromatography.

5.6 Ammonia. rho (NH3 · H2O) = 0.91 g/ml, excellent grade pure.

5.7 Ammonium formate-formic acid buffer solution. c (HCOONH4) = 0.01 mol/L, pH = 4.

Accurately weigh 0.315 g of ammonium formate (5.5) and dissolve it in an appropriate amount of water. After dissolving, transfer it to a 500 ml volumetric flask and dilute it with water.

Reduce the volume to the mark, mix well, and add about 70 µl of formic acid (5.4) to adjust the pH to 4.

5.8 n-hexane-dichloromethane mixed solution. 1 2.

Mix with n-hexane (5.3) and dichloromethane (5.2) in a volume ratio of 1. 2.

5.9 Standard stock solution of nitrophenols. rho = 100 mg/L.

It can be prepared with standard materials, the purity of standard materials is greater than 99.0%, dissolved in methanol (5.1), frozen below -10 ° C, Keep away from light. You can also purchase a certified standard solution directly and store it in accordance with the manufacturer's product instructions.

5.10 Standard solution for mixing nitrophenol compounds. rho = 5.00 mg/L (reference concentration).

Transfer an appropriate amount of standard stock solution of nitrophenol compounds (5.9), dilute with methanol (5.1), freeze at -10 ° C, Keep away from light and can be stored for 3 months.

5.11 Internal standard stock solution. rho = 5000 mg/L.

The internal standard is 2,4-dinitrophenol-d3, which can be prepared with standard materials. The purity of the standard material is greater than 98.0%. Methanol (5.1) is used.

Dissolve, store at -10 ° C or less, and protect from light. Certified standard solutions can also be purchased directly.

5.12 Internal standard use solution. rho =.200 µg/L (reference concentration).

Dilute the internal standard stock solution (5.11) with methanol (5.1) as needed, freeze it below -10 ° C, and store it in the dark to protect it.

Deposit for 3 months.

5.13 Filter. 0.22 µm PTFE filter.

5.14 Nitrogen. Purity >=99.99%.

6 Instruments and equipment

6.1 Liquid chromatography-triple quadrupole mass spectrometer. equipped with electrospray ionization source (ESI), with gradient elution and multiple reaction monitoring Test function.

6.2 Column. C18 reversed-phase liquid chromatography column with a particle size of 2.2 µm, a column length of 75 mm, and an inner diameter of 3.0 mm or other Similar performance columns.

6.3 Centrifuge. The maximum speed is not less than 4000 r/min.

6.4 Centrifuge tube with stopper. 10 ml.

6.5 Sample bottle. 250 ml ground glass bottle with stopper.

6.6 Micro-syringe or pipette. 10 µl, 50 µl, 100 µl, 500 µl, 1.0 ml.

6.7 General laboratory instruments and equipment.

7 Samples

7.1 Sample collection and storage

Collect samples in accordance with the relevant regulations of HJ/T 91 and HJ/T 164. The sample collection should be filled with sample vials (6.5), Leave no gaps. If the pH of the sample is not between 7-9 after collection, adjust the pH to 7 ~ 7 with ammonia (5.6) or formic acid (5.4).

9. Store refrigerated and protected from light below 4 ° C, and complete analysis within 7 days.

7.2 Preparation of test specimens

Cleaned samples can be filtered and injected directly for analysis. Filter the sample (7.1) through the filter (5.13) and discard at least 1 ml After the filtrate, transfer 1.0 ml of the filtered sample to a brown injection bottle, add 10.0 µl of the internal standard use solution (5.12), and mix Even to be tested.

Samples with complex matrices are cleaned and injected directly for analysis. Take a 5.0 ml sample (7.1) into a stoppered centrifuge tube (6.4) Add 1 ml of n-hexane-dichloromethane mixed solution (5.8), shake for 5 min, and centrifuge at 4000 r/min for 5 min.

Pipette 3 ml of the upper aqueous solution, filter it with a filter membrane (5.13), then transfer 1.0 ml of the filtrate into a brown sample vial, add Add 10.0 µl of internal standard use solution (5.12) and mix well for testing.

7.3 Preparation of blank samples

Use experimental water to replace the sample, and follow the same steps as the sample preparation (7.2) to prepare a laboratory blank sample Equipment.

8 Analysis steps

8.1 Instrument Reference Conditions

8.1.1 Reference conditions for liquid chromatography

Mobile phase A. ammonium formate-formic acid buffer (5.7), mobile phase B. methanol (5.1), the gradient elution procedure is shown in Table 1;

Flow rate. 0.2 ml/min; column temperature. 30 ° C; injection volume. 10 µl.

Table 1 Liquid chromatography gradient elution procedure

Time (min) Mobile phase A (%) Mobile phase B (%) 0.00 60 40 8.00 40 60 11.00 10 90 13.00 10 90 13.01 60 40 18.00 60 40

8.1.2 Mass spectrometry conditions

Ion source. Electrospray ion source (ESI), negative ion mode.

Monitoring method. Multiple response monitoring (MRM).

For the remaining conditions, see Appendix B.

8.1.3 Instrument tuning

There are some differences in the tuning parameters of instruments from different manufacturers, and they should be adjusted within the specified time and frequency according to the instrument's instruction manual.

The mass spectrometer is calibrated for instrument mass and resolution to ensure that the instrument is in the best test condition.

8.2 Calibration

8.2.1 Establishment of standard curve

Take an appropriate amount of nitrophenol compound standard solution (5.10) and dilute with water to prepare at least 5 concentration points Standard series of solutions, the mass concentrations of nitrophenol compounds in the standard solutions are 2.00 µg/L, 5.00 µg/L, 10.0 µg/L, 20.0 µg/L, 50.0 µg/L (this is the reference concentration), transfer 1.0 ml of the standard series solution to the brown injection bottle Add 10.0 µl of internal standard use solution (5.12) and mix well for testing.

According to the instrument reference conditions (8.1), the standard series solutions were measured from low concentration to high concentration. Target the mass concentration of the compound (µg/L) is the abscissa, and the ratio of the corresponding response value to the response value of the internal standard and the concentration of the internal standard the product of degrees is the ordinate, and a standard curve is established.

8.2.2 Standard Reference Spectrum

Under the instrument reference conditions recommended by this standard, the total ion chromatogram of the target compound is shown in Figure 1 (4 nitrophenols the compound's mass concentration was 10.0 µg/L).

1-2,6-dinitrophenol; 2-2,4-dinitrophenol-d3 (internal standard); 3-2,4-dinitrophenol; 4-4-nitrophenol; 5- 2,4,6-trinitrophenol.

Figure 1.Total ion current chromatograms of four nitrophenol compounds and internal standards.

8.3 Sample determination

Test the sample (7.2) according to the same instrument conditions as the standard curve establishment (8.2.1).

8.4 Blank test

The blank sample (7.3) was measured under the same instrument conditions as the sample measurement (8.3).

9 Calculation and representation of results

9.1 Qualitative analysis

Select 1 precursor ion and 2 daughter ions to monitor the target compound. Under the same experimental conditions, the absolute value of the relative deviation of the retention time of the target compound from the retention time of the target compound in the standard sample should be less than 2.5%; and the relative abundance (Ksam) of the qualifier ions of the target compound in the sample corresponds to that in a standard solution with a close concentration the relative abundance (Kstd) of the qualitative ions of There is a corresponding target compound.

Ksam (1)

In the formula. Ksam--the relative abundance of the qualifier ions of the target compound in the sample,%;

A2--The response value of the qualitative ion of the target compound in the sample by mass spectrometry.

A1--Secondary mass spectrometer response of the target compound in the sample.

std

In the formula. Kstd--the relative abundance of the qualifier ions of the target compound in the standard sample,%;

Astd2--Response value of qualitative ions of target compounds in the secondary mass spectrometry of the standard compound;

Astd1--Secondary mass spectrometer response of the target compound in the standard sample.

Table 2 Maximum allowable deviation of relative ion abundance during qualitative confirmation

Kstd /% Ksam allowable deviation /% Kstd > 50 ± 20 20 < Kstd<=50 ± 25 10 < Kstd<=20 ± 30 Kstd<=10 ± 50

9.2 Result calculation

The mass concentration (µg/L) of nitrophenol compounds in the sample is calculated according to formula (3).

Dii x= 1 (3)

In the formula. i-mass concentration of the i-th nitrophenol compound in the sample, µg/L;

i1-mass concentration of the i-th nitrophenol compound in the sample obtained from the standard curve, µg/L;

D--Dilution multiple.

9.3 Representation of results

When the measurement result is less than 10.0 µg/L, one decimal place is retained; when the measurement result is 10.0 µg/L or more, Keep three significant digits.

10 Precision and accuracy

10.1 Precision

Uniform blank spiked samples of nitrophenol compounds in 6 laboratories at 5.00 µg/L and 20.0 µg/L Six repeated measurements were performed. the relative standard deviations in the laboratory were 2.1% to 9.5% and 1.0% to 10% Relative standard deviations were 3.8% to 8.2% and 3.3% to 4.2%, respectively; repeatability limits were 0.7 µg/L to 0.8 µg/L and 2.3 µg/L ~ 3.3 µg/L; Reproducibility limits are 0.9 µg/L ~ 1.3 µg/L and 3.0 µg/L ~ 3.8 µg/L, respectively.

Six laboratories added spiked samples of nitrophenols to surface water at concentrations of 5.00 µg/L and 20.0 µg/L.

Six repeated determinations were performed. the relative standard deviations in the laboratory were 2.3% to 14% and 2.4% to 15%, respectively;

The standard deviations are 11% to 18% and 4.5% to 10%, respectively; the repeatability limits are 0.9 µg/L to 1.2 µg/L and 3.2 µg/L ~ 4.3 µg/L; Reproducibility limits are 1.8 µg/L ~ 2.7 µg/L and 3.9 µg/L ~ 6.6 µg/L, respectively.

Six laboratories spiked samples of industrial waste water with 5.00 µg/L and 20.0 µg/L of nitrophenols Six repeated determinations were performed. the relative standard deviations in the laboratory were 1.4% to 16% and 2.0% to 13%, respectively;

Relative standard deviations were 9.7% to 20% and 5.3% to 12%, respectively; repeatability limits were 0.9 µg/L to 1.3 µg/L and 2.9 µg/L ~ 4.8 µg/L; Reproducibility limits are 1.7 µg/L ~ 3.3 µg/L and 4.6 µg/L ~ 7.4 µg/L, respectively.

See Appendix C for method precision summary data.

10.2 Accuracy

Surface water samples spiked at 5.00 µg/L and 20.0 µg/L for nitrophenol compounds were performed in 6 laboratories 6 repeated spiking analysis and determination. The spiking recovery ranges are 77.1% ~ 119% and 77.0% ~ 116%, respectively.

The final values were 94.1% ± 28.7% ~ 97.5% ± 26.0% and 93.5% ± 18.3% ~ 101% ± 21.0%.

Six laboratories performed industrial wastewater samples with spiked concentrations of nitrophenols of 5.00 µg/L and 20.0 µg/L Six repeated spiking analyses were performed. the spiking recovery ranges were 72.6% to 109% and 75.0% to 112%, respectively.

The final yields were 91.8% ± 19.7% ~ 95.5% ± 22.5% and 98.7% ± 14.5% ~ 104% ± 10.2%.

Refer to Appendix C for method accuracy summary data.

11 Quality Assurance and Quality Control

11.1 Blank test

Determine at least one laboratory blank for every 20 samples or batches (<=20 samples/batch), and the measurement results should be lower than Method detection limit.

11.2 Calibration

A standard curve should be established for each batch of samples, and the correlation coefficient should be >=0.995.

Every 20 samples or each batch (<=20 samples/batch), a standard solution at the middle concentration point of the standard curve should be determined.

The relative error between the measurement result and the concentration at this point should be within ± 20%.

11.3 Parallel samples

Measure at least one parallel sample every 20 samples or batches (<=20 samples/batch). The relative deviation of parallel samples should be <= 25%.

11.4 Matrix Spiking

Determine at least one matrix spiked sample every 20 samples or batches (<=20 samples/batch). The matrix spiked recovery rate should be it is between 70% and 130%.

12 Waste treatment

The waste generated in the experiment should be collected centrally, sorted and stored, and properly labeled, and entrusted to a qualified unit for processing Management.

Appendix A

(Normative appendix) Method detection limit and determination limit when the injection volume is 10 µl, the method detection limits and lower detection limits of the four nitrophenol compounds are shown in Table A.1.

Table A.1 Method detection limits and determination limits

Compound name English name CAS number the detection limit (Mg/L) Lower limit of determination (Mg/L) 1 2,6-Dinitrophenol 2,6-Dinitrophenol 573-56-8 0.6 2.4 2 2,4-dinitrophenol 2,4-Dinitrophenol 51-28-5 0.4 1.6 3 4-nitrophenol 4-Nitrophenol 100-02-7 0.4 1.6 4 2,4,6-trinitrophenol 2,4,6-Trinitrophenol 88-89-1 0.5 2.0 Appendix B (Informative appendix) MS Reference Conditions

a) Spray voltage. 4500 V.

b) Ion source temperature. 600 ° C.

c) Atomizing gas pressure. 4.48 × 105 Pa (65 psi).

d) Auxiliary gas pressure. 5.52 × 105 Pa (80 psi).

e) Air curtain air pressure. 3.45 × 105 Pa (50 psi).

f) Multi-reaction monitoring conditions of target compounds are shown in Table B.1.

Table B.1 Multiple reaction monitoring conditions for target compounds

Compound name

Precursor ion

Product ion

Dwell time

Impact voltage

De-clustering voltage (V) Collision room entrance Voltage (V) Collision room exit Voltage (V) 2,6-dinitrophenol 183.1 79.0 * 0.05 64.1 40 40 4 10 2,4-dinitrophenol 183.0 108.9 * 0.05 123.0 26 51 12 7 4-nitrophenol 138.0 46.1 * 0.05 92.0 35 50 4 7 2,4,6-trinitro 227.9 181.9 * 0.05 198.0 26 68 6 0 2,4-dinitrophenol-d3 (internal standard) 186.1 112.0 * 0.05 126.0 27 62 2 4

Note 1. The ones with * are quantitative product ions of the secondary mass spectrometer and the other are qualitative product ions.

Note 2. For different mass spectrometers, the parameters may be different. The mass spectrometer parameters should be optimized to the best before the determination.

Appendix C

(Informative appendix) Method precision and accuracy Tables C.1 to C.2 and C.3 show the precision and accuracy of the methods, respectively.

Table C.1 Summary Table

Compound name

Spiked concentration (Mg/L) Total mean (Mg/L) Laboratory phase Standard deviation (%) Interlaboratory standard deviation(%) Repeatability limit r (Mg/L) Reproducibility limit R (Mg/L) 2,6-dinitrophenol 5.00 4.8 3.2 ~ 8.7 3.8 0.8 0.9 20.0 19.8 3.1 ~ 10 4.2 3.3 3.8 2,4-dinitrophenol 5.00 4.8 2.7 ~ 7.6 4.4 0.7 0.9 20.0 20.8 1.7 ~ 4.7 3.8 2.3 3.1 4-nitrophenol 5.00 4.9 2.6 ~ 7.2 7.6 0.7 1.2 20.0 20.1 2.5 ~ 6.2 3.3 2.6 3.0 2,4,6-trinitrophenol 5.00 5.0 2.1 ~ 9.5 8.2 0.8 1.3 20.0 20.6 1.6 ~ 6.3 4.0 2.7 3.4

Table C.2 Summary of precision of actual sample spiking

Compound

name

Sample type

Spiked concentration (Mg/L) Total mean (Mg/L) Relative in the laboratory standard deviation(%) Interlaboratory standard deviation(%) Repeatability limit r (µg/L) Limit of reproducibility R (µg/L) 2,6-Dinitrate Phenol Surface water 5.00 5.0 3.8 ~ 11 18 1.1 2.7 20.0 18.7 3.1 ~ 10 10 3.7 6.2 Industrial waste 5.00 4.6 4.8 ~ 16 16 1.3 2.4 20.0 19.8 2.0 ~ 8.5 12 2.9 7.4 2,4-Dinitrate Phenol Surface water 5.00 4.7 3.8 ~ 12 15 1.0 2.2 20.0 19.6 3.2 ~ 15 6.0 4.3 5.2 Industrial waste 5.00 5.6 3.1 ~ 14 18 1.1 3.0 20.0 21.4 2.5 ~ 10 5.8 3.6 4.8 4-nitro Surface water 5.00 4.8 2.3 ~ 8.8 14 0.9 2.0 20.0 20.3 4.2 ~ 7.9 10 3.3 6.6 Industrial waste 5.00 5.8 2.0 ~ 12 20 0.9 3.3 20.0 21.7 4.1 ~ 13 8.5 4.8 6.8 2,4,6-three Nitrophenol Surface water 5.00 4.84 2.6 ~ 14 11 1.2 1.8 20.0 19.7 2.4 ~ 10 4.5 3.2 3.9 Industrial wastewater 5.00 5.5 1.4 ~ 7.6 9.7 0.9 1.7 Compound name Sample type Spiked concentration (Mg/L) Total mean (Mg/L) Relative in the laboratory standard deviation(%) Interlaboratory standard deviation(%) Repeatability limit r (µg/L) Limit of reproducibility R (µg/L) 20.0 20.6 2.8 ~ 10 5.3 3.8 4.6

Table C.3 Summary of method accuracy

Compound name Sample type Sample concentration (Mg/L) Spiked concentration (Mg/L) Spike recovery range(%) Spike recovery P (%) Final spike recovery P ± 2 PS (%) 2,6-dinitrophenol Surface water ND 5.00 80.4 ~ 119 97.5 97.5 ± 26.0 20.0 77.0 ~ 102 93.5 93.5 ± 18.3 Industrial wastewater ND 5.00 72.6 ~ 109 92.3 92.3 ± 28.8 20.0 75.0 ~ 110 98.7 98.7 ± 24.6 2,4-dinitrophenol Surface water ND 5.00 77.1 ~ 117 94.1 94.1 ± 28.7 20.0 90.1 ~ 105 98.0 98.0 ± 11.5 Industrial wastewater 0.1 ~ 1.8 5.00 80.1 ~ 106 94.6 94.6 ± 19.7 20.0 91.9 ~ 108 102 102 ± 13.1 4-nitrophenol Surface water ND 5.00 81.9 ~ 118 97.1 97.1 ± 26.6 20.0 86.7 ~ 116 101 101 ± 21.0 Industrial wastewater 0.3 ~ 2.2 5.00 79.4 ~ 107 91.8 91.8 ± 19.7 20.0 99.0 ~ 112 104 104 ± 10.2 2,4,6-trinitro Surface water ND 5.00 81.2 ~ 113 96.9 96.9 ± 20.5 20.0 91.0 ~ 103 98.6 98.6 ± 8.96 Industrial wastewater 0.2 ~ 1.7 5.00 83.0 ~ 105 93.3 93.3 ± 17.0 20.0 87.0 ~ 106 98.7 98.7 ± 14.5 Note. ND means not detected.

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