SN/T 3323.3-2012 English PDF (SNT3323.3-2012)

This Part of SN/T 3323 specifies inductively coupled plasma atomic emission spectrometry (ICP-AES), the testing method to determine the lead, chromium, cadmium contents in mill scale. This Part is applicable to the determination of lead, chromium, cadmium contents in mill scale. The lower limit of determination for each element is shown in Table 1. Table 1 -- Lower limit of determination for each element

SN/T 3323.3-2012
ENTRY-EXIT INSPECTION AND QUARANTINE INDUSTRY
STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA
Mill scale - Part 3: Determination of lead, chromium,
cadmium - Inductively coupled plasma atomic emission
spectrometry
ISSUED ON: DECEMBER 12, 2012
IMPLEMENTED ON: JULY 01, 2013
Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Principle ... 4
4 Reagents and materials ... 5
5 Instruments ... 5
6 Specimen ... 6
7 Determination steps ... 6
8 Result calculation ... 7
9 Precision ... 8
Annex A (informative) Analysis wavelength of element and working conditions of instrument ... 9
Annex B (informative) Recommended solution concentration of calibration curve .. 10 Mill scale - Part 3: Determination of lead, chromium,
cadmium - Inductively coupled plasma atomic emission
spectrometry
1 Scope
This Part of SN/T 3323 specifies inductively coupled plasma atomic emission spectrometry (ICP-AES), the testing method to determine the lead, chromium, cadmium contents in mill scale.
This Part is applicable to the determination of lead, chromium, cadmium contents in mill scale. The lower limit of determination for each element is shown in Table 1. Table 1 -- Lower limit of determination for each element
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 6379.2, Measurement methods and results - Accuracy (trueness and precision) - Part 2: Determine the standard methods of measurement repeatability and reproducibility of the basic method
GB/T 6682, Water for analytical laboratory use - Specification and test methods GB/T 12806, Laboratory glassware - One-mark volumetric flasks
GB/T 12808, Laboratory glassware - One-mark pipettes
3 Principle
The specimen is decomposed by hydrochloric acid. Use the inductively coupled plasma Element Mass fraction %
atomic emission spectrometer for testing. Use the matrix matching method to eliminate the matrix effects.
4 Reagents and materials
Unless otherwise stated, all reagents are analytically pure and above. Water is grade two water specified in GB/T 6682.
4.1 Hydrochloric acid (ρ= 1.19g/mL): Guaranteed reagent.
4.2 High-purity iron powder: The iron mass fraction is greater than 99.98%. 4.3 Hydrochloric acid (1+1): Add 1 volume of hydrochloric acid (4.1) to 1 volume of water. Mix well.
4.4 Lead, chromium, cadmium standard solution (certified reference material): 1000μg/mL.
4.5 35mg/mL iron matrix solution: Weigh 3.5g of high-purity iron powder (4.2). Add 40mL of hydrochloric acid solution (4.3). Heat to dissolve. Use water to set volume constant in a 100mL volumetric flask.
5 Instruments
5.1 Inductively coupled plasma atomic emission spectrometer
5.1.1 Performance indicator
The spectrometer can also be sequential, multi-channel or full-spectral. In either type, it shall meet the following performance indicator:
The correlation coefficient (r) of the standard curve of each element to be tested is greater than 0.995.
5.1.2 Working state of instrument
Start the ICP-AES instrument. According to the operating procedures of the instrument, warm up the instrument and adjust various conditions and measurement parameters of the instrument, so that the performance of the instrument meets the requirements of 5.1.1.
5.1.3 Confirmation of spectral lines for determination
Choose the appropriate spectral lines according to the instrument conditions. The selection of the spectral lines shall follow the following rules:
volumetric flask. Use water to set the volume constant. Shake well. Determine on the inductively coupled plasma atomic emission spectrometer with selected operating parameters.
7.4 Preparation of working curve
Add 10mL of iron matrix solution (4.5), 8mL of HCl (4.1) into a set of 100mL volumetric flasks. Respectively pipette a certain amount of standard solutions of each element into the volumetric flask. Use water to dilute to the scale. Shake well. The content of the test element shall be within the range of the working curve made. The quantity of the series of standard solution shall be decided by the precision requirements. It requires not to be less than 4. See Annex B for the solution concentration of the recommended calibration curve.
7.5 Measurement
7.5.1 Measurement of calibration curve
Adjust the instrument according to the provisions in 5.1.2. Measure the spectral intensity of each test element in the series solutions of calibration curve (7.4) at the analysis line in turn. The instrument automatically returns to establish a linear equation. Its correlation coefficient (r) shall comply with 5.1.1 regulations.
7.5.2 Determination of test solution
Introduce the test solution (7.3) into the plasma in turn. Respectively determine the spectrum strength of each test element and internal standard elements at the same analysis line. The instrument shall automatically calculate the corresponding concentration of each element according to the calibration curve.
8 Result calculation
Calculate the content of each element according to formula (1), in mass fraction. Where,
Xi - The content of each test element i (mass fraction), %;
ci - The mass concentration of test element found from the working curve, in micrometers per milliliter (μg/ mL);
V - The constant volume of test solution, in milliliters (mL);