GBZ/T 307.1-2018Determination of cadmium in urine -- Part 1: Graphite furnace atomic absorption spectrometric method (English PDF)

Foreword

This standard is formulated in accordance with the Law of the People's Republic GBZ/T 307 "Determination of cadmium in urine" is divided into two parts.

-- Part 1. Graphite furnace atomic absorption spectrometry;

-- Part 2. Inductively coupled plasma mass spectrometry.

This part is the first part of GBZ/T 307.

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This section replaces WS/T 32-1996 "Method for the determination of cadmium in urine by graphite furnace atomic absorption spectrometry".

Compared with WS/T 32-1996, the main changes are as follows.

-- The use of new matrix modifiers;

-- Improved standard formulation and sample handling methods.

This section is mainly drafted by. China Center for Disease Control and Prevention, Occupational Health and Poison Control Institute, Guangdong Provincial Occupational Disease Prevention and Treatment Institute, Jiangsu Provincial Center for Disease Control and Prevention, Shandong Institute of Occupational Health and Occupational Diseases.

1 Scope

This part of GBZ/T 307 specifies a graphite furnace atomic absorption method for the determination of cadmium in urine.

This section applies to the determination of cadmium in urine of occupational contacts.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document.

For undated references, the latest edition (including all amendments) applies to this document.

General rules for biological monitoring of GBZ/T 295 occupational population

3 Principle

A urine sample (hereinafter referred to as a urine sample) is diluted with a mixed solution of palladium chloride and nitric acid (ie, a matrix modifier) at a wavelength of 228.8 nm.

Next, the concentration of cadmium was determined by graphite furnace atomic absorption spectrometry.

4 Instruments

4.1 Covered polyethylene plastic bottle. 100 mL.

4.2 Volumetric flask. 10 mL.

4.3 stoppered polyethylene centrifuge tube. 1.5 mL.

4.4 Micropipette. The range is 20 µL ~.200 µL, 100 µL ~ 1000 µL.

4.5 Atomic Absorption Spectrometer. with graphite furnace, cadmium hollow cathode lamp and background correction device. Refer to Table 1 for instrument operation reference conditions.

Table 1 Instrument operation reference conditions

step

temperature

Heating time

Residence time

Carrier gas flow

mL/min

Drying 110 5 10 250

Drying 130 10 20 250 Ashing 500 20 30 250 Atomization 1600 0 3 0 Clear 2300 1 5 250 Note. The above conditions are provided for the convenience of standard users. If the conditions are changed, the same effect should be achieved.

5 Reagent

5.1 Deionized water.

5.2 Nitric acid, excellent grade pure, rho20=1.42 g/mL.

5.3 Matrix modifier. Weigh 0.20 g of palladium chloride, add slightly heat to 10.0 mL of nitric acid, shake well, and dilute to 500 mL with water. Storage Store in a brown reagent bottle and store it for 1 year in cold storage and protected from light.

5.4 Blank urine sample. normal human urine that does not touch cadmium, add nitric acid in a ratio of 100.1, and mix.

5.5 Standard solution. Use a nationally recognized standard solution.

6 Sample collection, transportation and storage

6.1 Collect 100 mL of urine sample in polyethylene plastic bottle, add nitric acid in a ratio of 100.1, mix well, and measure urinary muscle as soon as possible.

anhydride.

6.2 Sample blank. randomly take 2 parts of the urine collection container with the same batch number as the sample collection, and add water equivalent to the sample collection amount.

The product is blank and transported and stored at the same time as the sample.

6.3 Sample transportation. Store the collected samples and sample blanks in a clean container for refrigerated transport.

6.4 Sample storage. Store at 4 °C for 2 months.

7 Analysis steps

8 Calculation

Calculate the concentration of cadmium in the urine sample according to formula (1).

In the formula.

C - the concentration of cadmium in urine, in micrograms per gram of creatinine (µg/g creatinine);

C0 - the concentration of cadmium in the urine sample obtained from the working curve or the regression equation in micrograms per liter (µg/L);

Cr - Urinary creatinine concentration in grams per liter (g/L).

9 Description

9.1 The detection limit of this method is 0.17 µg/L, the lower limit of quantification is 0.50 µg/L; the measurement range is 0.50 µg/L to 15.0 µg/L. relatively the standard deviation ranges from 1.4% to 7.5% (n=6).

9.2 The injection volume of this method can be determined according to the specific conditions of the instrument, generally choose 10 µL ~ 20 µL.

9.3 In this method, the matrix has an influence on the measurement. The sample should be treated in the same way as the working curve series solution. If the cadmium concentration in the sample is super Over the measurement range, the urinary cadmium working curve range can be increased to 30.0 µg/L, urine 0.10 mL, respectively, added 0.90 mL matrix improvement the agent was diluted and measured. When measuring cadmium in normal urine, 0.30 mL of urine can be taken and diluted with 0.60 mL of matrix modifier to determine.

9.4 Volumetric flasks and other supplies should be soaked in a 1.1 nitric acid solution overnight, washed sequentially with tap water, laboratory water, and added with 1% the background test is carried out by using a nitric acid solution as a method to be tested, and the test result should be less than the detection limit. Covered with polyethylene plastic bottle, with polyethylene Disposable items such as heart tube and micropipette tips should also be used after sampling.

9.5 Quality control of the testing process shall be carried out in accordance with the requirements of GBZ/T 295.