[Determination of lead in grape wine by graphite furnace atomic absorption spectrometry with ammonium dihydric phosphate as modifier]

Abstract

Ammonium dihydric phosphate (NH4H2PO4), palladium chloride, nickelous nitrate and magnesium nitrate were used as modifiers respectively, to directly detect lead in grape wine with graphite furnace atomic absorption spectrometry(GFAAS). The results showed that NH4H2PO4 might be the best modifier. It was found that the organic matter in grape wine interfere with the determination. To remove the interference and detect lead directly with GFAAS, not only did samples need to be diluted with 4 to 10 times sample volumes of de-ionized water, but also the standard addition method was used. The method had good precision and accuracy when concentration of lead was above 10 micrograms.L-1, the relative standard deviations of lead were between -5.4% and 6.2%.