ISO 11723:2016 pdf free
ISO 11723:2016 pdf free.Solid mineral fuels一Determination of arsenic and selenium一Eschka’s mixture and hydride generation method
The spectrometer and hydride generation apparatus are optimized according to the manufacturer’s advice. Arsenic is measured at 193,7 nm and selenium at 196,0 nm.
NOTE 1 It is not possible to specify instrumental operating conditions because the instruments available vary significantly and incorporate alternative methods of hydride generation and atomization.
NOTE 2 As an alternative to the use of an atomic absorption spectrometer or an atomic fluorescence spectrometer, an inductively coupled plasma atomic emission spectrometer equipped with hydride generation apparatus can be used.
Transfer the prepared solution (8.4) into the hydride generation apparatus, add the appropriate amount of sodium borohydride solution (5.5) or a pellet of sodium borohydride and transport the generated hydride of the analyte into the atomization device in the light path of the spectrometer. Note the absorbance or fluorescence signal (peak height or peak area).
Repeat the measurement procedure for all blanks, calibration standard solutions and test solutions.If the reading for any test solution is higher than that of the highest calibration standard solution, then the test solution shall be diluted with the blank test solution and remeasured, at the same time noting the dilution factor.
From the readings obtained on the calibration standard solutions, construct a calibration graph of concentration of analyte, in ug/kg or ug/l, versus instrument reading (peak height or peak area). The concentration of arsenic or selenium in the sample test solution is obtained from the graph.Using the prepared calibration graph, convert the readings obtained on the test and blank test solutions
to concentrations in μg/kg of test solution or μg/I.
The results of duplicate determinations carried out at different times in the same laboratory, by the same operator, with the same apparatus, on representative portions taken from the same analysis sample, shall not differ by more than the value shown in Table 1.ISO 11723 pdf free download.
