DETERMINATION OF LEAD IN WINE BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROPHOTOMETRY - INTERLABORATORY STUDY

An interlaboratory study of a graphite furnace atomic absorption spect rophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to m inimize matrix effects between standards and samples. Six wine test ma terials were prepared and sent to participants as 12 blind duplicate o r split level samples. There was good agreement between results obtain ed from participants and target values (24-279 mu g/L) obtained with a n inductively coupled plasma-mass spectrometry method. The precision o f the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard dev iations ranged from 3 to 17%, Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for offi cial purposes.