Detection of manganese in saliva with graphite furnace atomic absorption spectrometry

Objective To establish the graphite furnace atomic absorption spectrometry method to examine the manganese in saliva.

Methods After centrifuge of saliva, 0.5 mL of the supernatant was digested with nitric acid. 0.2% nitric acid was added to the constant volume 2 mL. The specimen was measured with atomic absorption spectrometer. Then samples of 234 welding workers and 135 control workers were detected.

Results The best ashing temperature of the method was 1 100℃, and the optimum atomic temperature was 1 900℃. The linear regression equation was Y=0.015 87 x + 0.004 80 with the correlation coefficient 0.999 2(P < 0.01). The characteristics of concentration was 5.4 pg/0.004 4 Abs, and the detection limit was 5.8 pg. The recovery rate was 85%-106% with relative standard deviation 1.5%-1.8%. The average value of saliva manganese concentration was (7.65 ±5.57) g/L and(10.63 ±12.37) g/L in the control and welding workers, respectively(P < 0.01). The concentration of manganese varied among workers with lower or higher exposure level, (7.68 ±6.98)g/L vs.(13.38 + 15.36) g/L(P < 0.01).

Conclusion The method is highly sensitive and accurate, easy to manipulate and well repeated. These suggested the method may be suitable for sampling and determination of manganese in human body.