Mikuła B, Puzio B
Zakładu Chemii Analitycznej Uniwersytetu Slaskiego.
Rocz Panstw Zakl Hig. 1995;46(1):31-7.
The purpose of the study was utilization of emission atomic absorption spectrometry with excitation in induction-coupled plasma, and molecular spectrometry for determination of lead in milk and dairy products after condensation in ammonia atmosphere. Two methods were proposed for lead condensation on lanthanum carrier--in form of hydroxide or sulphide. By coprecipitation of lead on lanthanum in ammonia atmosphere lead separated and selectively condensed. Other metals (Zn, Cd, Cu) coexistent in food products remained as amino complexes in the solution. The sediment remaining after lead condensation was dissolved in 2 mol/dm3 hydrochloric acid solution. The selected conditions of lead separation and condensation make possible determination of the metal in the concentrations from 0.01 mcg/ml to 0.2 mcg/ml by the ICP-ARS and dithizone methods. The method of condensation and determination was used for lead determination in milk and dairy products in concentrations below 1.5 x 10(-5)%. The studied food products were mineralized with concentrated HNO3, H2SO4 and perhydrol. This mineralization method makes it possible to determine in one mineralisate directly copper and zinc by ICP-ARS and dithizone methods, and lead after condensation. The obtained results were precise and reproducible.
本研究的目的是利用电感耦合等离子体激发发射原子吸收光谱法和分子光谱法，测定在氨气氛中浓缩后的牛奶和乳制品中的铅。提出了两种在镧载体上浓缩铅的方法——以氢氧化物或硫化物的形式。通过在氨气氛中铅在镧上的共沉淀，铅得以分离并选择性浓缩。食品中共存的其他金属（锌、镉、铜）仍以氨基络合物的形式留在溶液中。铅浓缩后剩余的沉淀物溶解于2 mol/dm³盐酸溶液中。所选择的铅分离和浓缩条件使得通过电感耦合等离子体原子发射光谱法（ICP - ARS）和双硫腙法能够测定浓度为0.01 mcg/ml至0.2 mcg/ml的金属。浓缩和测定方法用于测定牛奶和乳制品中浓度低于1.5×10⁻⁵%的铅。所研究的食品用浓硝酸、硫酸和过氧化氢进行矿化。这种矿化方法使得能够在一种矿化产物中直接通过电感耦合等离子体原子发射光谱法和双硫腙法测定铜和锌，并在浓缩后测定铅。所得结果准确且可重复。
