AS ISO 13547.1:2015 Copper, lead, zinc and nickel sulfide concentrates—Determination of arsenic
7.7 Preparation of test solutions
Quantitatively, transfer the solutions fromstep 7.6 to a 200 ml volumetric flask and dilute to approximately 150 ml of deionized water. Allow this solution to cool to room temperature, then dilute to 200 ml of water and mix again.
7.8 Preparation of calibration solutions
Using arsenic standard (4.21), prepare a series of calibration standards as per Table 1. Transfer the appropriate volumes of arsenic standard (4.21) using pipettes into 100 ml volumetric flasks containing 10 ml of hydrochloric acid (4.8) and 15 ml of iron chloride solution (4.16). Fill up nearly to the mark with water, mix, and equilibrate at room temperature, then fill up exactly to the mark and mix again.
7.9 Preparation of arsenic calibration curve
Set up the ICP-AES (5.3) according to the guidelines set out in 5.3. Adjust the instrument read-out scale to zero. Aspirate each calibration solution as prepared in step 7.8 through the ICP-AES and record the emission intensities. Manually or electronically plot a curve of the average emission intensities versus the mass (μg) of arsenic.
Use ISO 8466-2 as a guide to determine the acceptability of the calibration curve.
7.10 Determination of arsenic content in test solutions
After calibrating the ICP-AES (5.3), determine the arsenic content in the test solutions [7.8]. Adjust the instrument read-out scale to zero. Aspirate the first duplicate of each sample through the ICP-AES and record the emission intensities checking the zero regularly.
Check the calibration of the instrument, then aspirate the second duplicate of each sample in the reverse order through the ICP-AES and record the emission intensities checking the zero regularly.
Determine the mass of arsenic in each test sample (FAs, in μg) from the curve determined in 7.9.
If more than 10 μg of arsenic is found in the blank test, then this shall be investigated and the results for the samples shall not be reported.