Abstract
A flameless atomic absorption spectroscopy method has been developed for the measurement of chromium. Background correction has been modified by recording non-atomic absorption separately from atomic absorption on a double-pen recorder. This was achieved by using the prime spectral line of uranium (358·5 nm, within 0·6 nm of that of chromium—357·9 nm) and was possible only because of the absence of uranium from the plasma samples. Masking of the analytical signal at atomisation by non-atomic absorption was thus eliminated and gave the method a sensitivity of 3 pg and a detection limit of 150 pg/ml. Postprandrial plasma chromium values were measured in 32 insulin-treated diabetics (1·65 ±0·15 ng/ml), in 53 non-insulin treated diabetics (2·05 ± 0·16 ng/ml), and in 144 control non-diabetics (2·00 ± 0·14 ng/ml). The difference between the mean plasma chromium level of the insulin-treated diabetics and both the non-insulin treated diabetics and the control groups was statistically significant (p<0·05).