GBZ/T 315-2018Determination of chromium in blood -- Graphite furnace atomic absorption spectrometric method (English PDF)

Foreword

This standard is formulated in accordance with the Law of the People's Republic this standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces WS/T 38-1996 "Method for the determination of chromium in blood by graphite furnace atomic absorption spectrometry".

Compared with WS/T 38-1996, the main changes are as follows.

-- The operating conditions of the instrument are changed to the reference conditions for instrument operation;

-- Improved standard formulation and sample handling methods;

-- Increased use of matrix modifiers.

This standard was drafted. Jiangsu Provincial Center for Disease Control and Prevention, China Center for Disease Control and Prevention, Occupational Health and Poison Control Institute, Guangdong Provincial Occupational Disease Prevention and Control Institute, Wuxi Municipal Center for Disease Control and Prevention, Nanjing Occupational Disease Prevention and Control Institute.

1 Scope

This standard specifies graphite furnace atomic absorption spectrometry for the determination of chromium in blood.

This standard applies to the determination of chromium in the blood 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.

GBZ/T 295 General rules for occupational health biological monitoring WS/T 97 urinary creatinine spectrophotometric method WS/T 98 urinary creatinine by reversed-phase high performance liquid chromatography

3 Principle

The blood sample was diluted with a matrix modifier and measured by graphite furnace atomic absorption spectrometry at a wavelength of 357.9 nm.

4 Instruments

4.1 Volumetric flask, 10 mL, 100 mL, 500 mL, 1000 mL.

4.2 Pipettes, 50 µL,.200 µL, 1000 µL.

4.3 Balance, the sensitivity is 0.1mg.

4.4 Covered plastic centrifuge tube, 1.5 mL.

4.5 Blood collection supplies, blood collection needles, sterile cotton swabs, lithium heparin (sodium) vacuum blood collection tubes, etc.

4.6 Atomic absorption spectrometer with graphite furnace atomizer, Zeeman calibration device, chrome hollow cathode lamp.

5 Reagent

5.1 Experimental water, deionized water or quartz glass sub-boiling distilled water.

5.2 Nitric acid, high purity.

5.3 Triton X-100, chromatographically pure.

5.4 Magnesium nitrate hexahydrate, excellent grade.

5.5 Matrix modifier. Weigh 0.865 g of magnesium nitrate hexahydrate dissolved in water, add 1.0 mL Triton X-100, 2.0 mL Nitric acid, make up to 1000 mL.

5.6 Bovine blood, heparin anticoagulation, stored at -20 ° C, shake to room temperature when used. Low background blood can also be used.

5.7 Chromium standard stock solution. Accurately weigh the reference material potassium dichromate (110 °C, baking for 2 h) 1.4315 g (accurate to 0.0001 g), After dissolving with a small amount of water, transfer the whole amount to a 500 mL volumetric flask, add 5.0 mL of nitric acid, dilute to volume with water, and mix. This solution per ml Contains 1.0 mg of chromium. Or purchase a standard stock of chromium monoliths certified by the state and awarded a certificate of reference material.

5.8 Chromium standard intermediate solution [rho(Cr)=5.0 µg/mL]. The chromium monolith standard stock solution is diluted to a concentration of 5.0 with a matrix modifier.

Standard intermediate solution of µg/mL.

5.9 Chromium standard series solution. respectively absorb chromium standard intermediate solution (5.0 µg/mL) 0.0 µL, 30.0 µL, 50.0 µL, 100.0 µL, 200.0 µL, 400.0 µL, and 800.0 µL in a 10 mL volumetric flask, dilute to the mark with a matrix modifier, and mix. In each volumetric flask each liter contains 0.0 µg, 15.0 µg, 25.0 µg, 50.0 µg, 100.0 µg,.200.0 µg, and 400.0 µg of chromium. Temporary Now equipped.

6 Sample collection, transportation and storage

According to the requirements of GBZ/T 295, the venous blood of workers exposed to chromium should be collected more than 2.0 mL, shake immediately and refrigerate. Sample can be guaranteed at 4 °C it can be stored for two weeks at -20 °C for two months.

7 Analysis steps

8 Calculation

The concentration of chromium in the blood sample is calculated according to formula (1).

1cc = ...(1)

In the formula.

c -- the concentration of chromium in the blood sample, in micrograms per liter (µg/L);

C1 -- The concentration of chromium in the blood sample calculated by the regression equation in micrograms per liter (µg/L).

9 Description

9.1 The detection limit of the method is 0.47 µg/L, and the lower limit of quantification is 1.56 µg/L; the method range is 1.56 µg/L to 400.0 µg/L.

Within this range, the correlation coefficient is >0.9990; the precision within the method range is 0.6% to 6.6% (the blood chromium concentration is 4.1 µg/L to 306.1).

Gg/L, n=6); the inter-assay precision range is 1.0% to 6.7% (blood chromium concentration is 4.1 µg/L to 302.4 µg/L, n=6);

The recovery of spiked blood samples was 94.5 %~104.1% (the concentration of blood chromium was 3.2 µg/L~101.2 µg/L, and the spiked concentration was 25.0.

Gg/L ~ 300.0 µg/L, n = 6).

9.2 This method is used for blood chromium determination. The minimum sample volume of blood sample is 50.0 µL.

9.3 All the utensils used in the experiment should be soaked in nitric acid solution (1 4) overnight, rinsed repeatedly with water, and finally rinsed with deionized water.

9.4 When this method is used for the determination of blood chromium, it should not be analyzed by graphite furnace atomic absorption spectrometer with xenon lamp calibration device, otherwise it will lead to the detection limit and the lower limit of quantitation are both high.

9.5 1000.0 µg/mL of Na, K, Ca2, Mg2, Cu2, Zn2, 500.0 µg/mL of Fe3, 100.0 µg/mL of Li, Si the Ba2, Be2, Al3, Ni2, Mn2, and Pb2 ions do not interfere with the measurement.