System peaks Selenium

In the method described by Willie et al. [167] atomic absorption measurements were made with a Perkin-Elmer 5000 spectrometer fitted with a Model HGA 500 graphite furnace and Zeeman effect background correction system. Peak absorbance signals were recorded with a Perkin-Elmer PRS-10 printer-sequencer. A selenium electrodeless lamp (Perkin-Elmer Corp.) operated at 6W was used as the source. Absorption was measured at the 196.0nm line. The spectral band-pass was 0.7nm. Standard Perkin-Elmer pyrolytic graphite-coated tubes were used in all studies. 

Human selenosis has been reported from the Enshi district, Hubei Province, China. Between 1923 and 1988,477 cases of human selenosis were reported, 338 resulting in hair and nail loss and disorders of the nervous system. In one small village, the population was evacuated after 19 of 23 people suffered nail and hair loss, and all the livestock had died from selenium poisoning. Cases of selenosis in pigs reached a peak between 1979 and 1987, when 280 out of 2,238 pigs were affected in one village. 

Furthermore, the potentiating effect in the oxytocic assay system previously found for amorphous deamino-l-seleno-oxytocin was retained by the crystalline analog, thus indicating a non-equivalence of the selenium moieties in position 1 and 6. In this context it should be mentioned that we demonstrated the non-equivalence of both selenium moieties also by another approach, namely, by comparing the circular dichroism spectra of deamino-l-seleno-oxytocin and deamino-6-seleno-oxytocin (16). While the spectrum of deamino-l-seleno-oxytocin exhibits negative peaks at 300, 280 and 235 m ji, and a positive peak at 258 mp, that of deamino-6-seleno-oxytocin exhibits positive peaks at 290 and 260 mp and negative peaks at 280 and 237 mp (Fig. I). 

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