Determination of cadmium, lead and thallium in highly saline hemodialysis solutions by potentiometric stripping analysis (PSA).
Potentiometric stripping analysis (PSA) was investigated to assay simultaneously cadmium, lead and thallium present as contaminants in highly saline solutions used in hemodialysis. The saline matrices were sodium, potassium, magnesium and calcium chlorides, sodium acetate, sodium bicarbonate and glucose, which constitute concentrates for hemodialysis. A 1000mugmL(-1) Hg(II) solution was used to prepare the mercury film electrode (MFE) and to carry out the stripping step. After a 30s accumulation interval the analytes were simultaneously detected in the saline matrices without using masking agents. Determination limits of 80ngL(-1) for cadmium and thallium, and 50ngL(-1) for lead were calculated and a R.S.D. ranging from 0.5 to 2.2% (n = 3) was obtained measuring the analytes directly in commercial hemodialysis saline solutions. Recoveries from spiked samples ranging from 94.6 to 102.0% were obtained. The investigated metals were found in concentrations ranging from 2.7 to 5.7mugL(-1) for cadmium, 27.7 to 75.8muL(-1) for lead and 9.6 to 18.7mugL(-1) for thallium in commercial hemodialysis solutions. The PSA method showed to be adequate to the quality control of saline concentrates for hemodialysis.
do Nascimento
Paulo Cícero
PC
Departamento de Química, Universidade Federal de Santa Maria, 97111-970 Santa Maria, RS, Brazil.
Bohrer
Denise
D
de Carvalho
Leandro Machado
LM
Caon
Carla Eliete
CE
Pilau
Eduardo
E
Vendrame
Zilda Baratto
ZB
Stefanello
Raquel
R