ICP-MS as well as influencing the concentration and retentiontime of
the analytes in the ICP torch.To optimize the carrier and supplemental
gas flow rates, 0.1ngofCd (10μLstandardsolution) was employed to
acquire the Cd signals of the ICP-MS at different gas flow rates(Figs.3
and4).The Cd responses notably increased prior to300mL/min for
the supplemental gas and 700mL/min for the carrier gas be cause the
transportation efficiencies were insufficient at lowergas flow rates;
subsequently,the Cd signals dropped with increasing gas flow rates
above300mL/min for the supplemental gas and 800mL/min for the
carrier gas due to the dilution effects at higher gas flow rates.
To optimize the gas flow rates for real food samples, approximately 2mg each of rice,spinach,and porkliver CRMs(GBW10045,
GBW10015,andGBW10051)were employed to examine the Cdintensity changes during ICP-MS. Results similar to those from the above Cd
standard solution were observed; the optimum response was also obtained at300mL/min for the supplemental gas and700mL/min for
the carrier gas.Thus,these flow rates were chosen for subsequent work