ISO 15247:2015 pdf free

ISO 15247:2015 pdf free.Zinc sulfide concentrates一Determination of silver content一Acid dissolution and flame atomic absorption spectrometric method
Taking multiple increments, extract a test portion from the test sample in such a manner that it is representative of the whole contents of the dish or tray. Weigh to the nearest 0,1 mg approximately 1 g of test sample. At the same time as the test portion is weighed, weigh test portions for the determination of hygroscopic moisture in accordance with ISO 9599.
Alternatively, the method specified in Annex A can be used to prepare predried test portions directly from the laboratory sample.
Carry out the determinations at least in duplicate and as far as possible under repeatability conditions on each test sample.
NOTE Repeatability conditions exist where mutually independent test results are obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within short intervals of time.
Carry out a blank test in parallel with the analysis using all reagents specified in the determination but omitting the test portion. The purpose of the blank test in this method is to check the quality of the reagents. If a significant blank value is obtained as a result of the blank test, check all reagents and rectify the problem.
Determine the silver content of the test portion by flame atomic absorption spectrometry using calibration solutions (4.9). As a guide, the following atomic absorption settings are recommended;however, the instrument should be optimized to give maximum sensitivity and as near as practical to a linear relationship between absorbance and concentration.
Perform three measurements on each standard solution. Calculate, to three significant figures, the mean absorbance for each standard solution, provided that the range of values does not exceed 0,003 absorbance units. If this range is exceeded, repeat the calibration.
The test solutions should be treated in the same manner. Plot a calibration graph of absorbance versus concentration of silver.
During all FAAS determinations, the test solutions and calibration solutions should have the same temperature as well as the same acid concentrations.ISO 15247 pdf free download.