The determination of total germanium in real food samples including Chinese herbal remedies using graphite furnace atomic absorption spectroscopy

Abstract

This paper outlines the development of a method for the determination of total germanium in foodstuffs utilising graphite furnace atomic absorption. It was found that by varying the drying times interferences could be minimised. Metals including calcium, cobalt, copper, magnesium, nickel, lead and zinc were tested for potential interferences. It was found experimentally that none of the listed metals interfered with this method. The optimal furnace conditions were determined to be; drying for 80 s (85 °C for 30 s, 95 °C for 40 s and 120 °C for 10 s), ashing at 700 °C for 8 s and atomisation at 2600 °C for 3.3 s followed by a tube clean for 2 s at 2800 °C and a lamp current of 5 mA for analysis at 265.2 nm. The method was found to have a linear range of 3.3–125 μg/l with a limit of detection and a characteristic mass of 0.051 and 0.053 ng germanium, respectively. The samples chosen for analysis include vegetables, fruit juices, Chinese herbal remedies and over the counter formulations. It was found that the aloe vera tablet, ginseng tablet and ginger tablet contained 20.83, 5.48 and 9.96 μg/g. Other foods found to contain germanium were potato, garlic and carrot, having 1.85, 2.79 and 0.60 μg/g of germanium. The food found to contain the highest concentration of germanium was Soya mince having 9.39 μg/g.