Relationship between the cervical uterine cancer evolution and selenium concentration in urine determied by NAA

Abstract

Neutron activation analysis of Se in urine reaches an optimum sensitivity (few ppb) and precision (±12%) when the traces are complexed without using a carrier by ammonium pryrrolidindithiocarbamate (APDC) at pH 1.5–2 and adsorbed on activated carbon filters. In this way the selenium traces analysis have been carried out through77mSe in 45 urine samples on a pre-separation basis by cyclic activation ofthe carbon filters. The selenium concentration in our blanks is virtually zero, because APDC proved to be selnium free and selenium mass in 50 mg of activated carbon used as a filter is 20 times below our qualitative detection limit and 144 times below our quantitative detection limit. The samples were first of day urine from healthy and ill women suffering cervical uterine cancer, at different evolution stages: incipient, intemediate and advanced, with no treatment, and surgery, radiotherapy, chemotherapy, or a combined treatment. The results show a consistent tred to increase the selenium trace concentration during the intemediate stage, whereas it is the same than nomal for incipient cases, and it decreases to the lowest concentrations for advanced cases.