PREPARATION OF HAIR FOR MEASUREMENT OF ELEMENTS BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY (ICP-MS)

The preparation of hair for the determination of elements is a critica l component of the analysis procedure. Open-beaker, closed-vessel micr owave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrate d nitric acid in an atmospheric pressure-low-temperature microwave dig estion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample w eights ranging from 0.08 to 0.3 g. After digestion, samples are analyz ed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr , Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U . Benefits of the APLTMD include reduced contamination and sample hand ling, and increased precision, reliability, and sample throughput.