Determination of ultratrace bismuth in milk samples by atomic fluorescence spectrometry.
A sensitive procedure was developed for determination of bismuth (Bi) in milk samples by hydride generation atomic fluorescence spectrometry (HG-AFS) after microwave-assisted sample digestion with HNO3 and H2O2. The method provides a sensitivity of 1832 fluorescence units (ng/mL) with a detection limit of 0.01 ng/mL, which corresponds to 20 pg absolute limit of detection, equivalent to 0.50 ng/g in the original sample. Application of the methodology to cow milk samples from the Spanish market showed the presence of Bi at a concentration of 11.8-28.8 ng/g, which compared well with data obtained after dry ashing of samples and with data obtained by inductively coupled plasma-mass spectrometry after microwave-assisted digestion.
D000818:Animals; D001128:Argon; D001729:Bismuth / Q000032:analysis*; D001894:Borohydrides / Q000032:analysis; D005453:Fluorescence; D007202:Indicators and Reagents; D008872:Microwaves; D008892:Milk / Q000737:chemistry*; D011786:Quality Control; D012680:Sensitivity and Specificity; D013030:Spain; D013057:Spectrum Analysis / Q000379:methods*
D001894:Borohydrides; D007202:Indicators and Reagents; D001128:Argon; C025364:sodium borohydride; D001729:Bismuth