Agrawal Y K, Sharma K R
Analytical Laboratory, Institute of Pharmacy, Nirma University of Science and Technology, Sarkhej-Gandhinagar Highway, Ahmedabad 382 481, India.
Talanta. 2005 Jul 15;67(1):112-20. doi: 10.1016/j.talanta.2005.02.015. Epub 2005 Mar 25.
A new functionalized calix[6]crown hydroxamic acid is reported for the speciation, liquid-liquid extraction, sequential separation and trace determination of Cr(III), Mo(VI) and W(VI). Chromium(III), molybdenum(VI) and tungsten(VI) are extracted at pH 4.5, 1.5M HCl and 6.0M HCl, respectively with calixcrown hydroxamic acid (37,38,39,40,41,42-hexahydroxy7,25,31-calix[6]crown hydroxamic acid) in chloroform in presence of large number of cations and anions. The extraction mechanism is investigated. The various extraction parameters, appropriate pH/M HCl, choice of solvent, effect of the reagent concentration, temperature and distribution constant have been studied. The speciation, preconcentration and kinetic of transport has been investigated. The maximum transport is observed 35, 45 and 30min for chromium(III), molybdenum(VI) and tungsten(IV), respectively. For trace determination the extracts were directly inserted into the plasma for inductively coupled plasma atomic emission spectrometry, ICP-AES, measurements of chromium, molybdenum and tungsten which increase the sensitivity by 30-fold, with detection limits of 3ngml(-1). The method is applied for the determination of chromium, molybdenum and tungsten in high purity grade ores, biological and environmental samples. The chromium was recovered from the effluent of electroplating industries.
报道了一种新型功能化杯[6]冠异羟肟酸，用于铬(III)、钼(VI)和钨(VI)的形态分析、液-液萃取、顺序分离及痕量测定。在大量阳离子和阴离子存在下，分别于pH 4.5、1.5M盐酸和6.0M盐酸介质中，用杯冠异羟肟酸（37,38,39,40,41,42-六羟基-7,25,31-杯[6]冠异羟肟酸）在氯仿中萃取铬(III)、钼(VI)和钨(VI)。研究了萃取机理。研究了各种萃取参数，如合适的pH/M盐酸、溶剂的选择、试剂浓度的影响、温度及分配常数。研究了形态分析、预富集及传输动力学。铬(III)、钼(VI)和钨(IV)的最大传输时间分别为35、45和30分钟。对于痕量测定，将萃取液直接注入等离子体中，用于电感耦合等离子体原子发射光谱法（ICP-AES）测定铬、钼和钨，灵敏度提高了30倍，检测限为3ngml(-1)。该方法用于高纯矿石、生物和环境样品中铬、钼和钨的测定。从电镀工业废水中回收了铬。
