Exploration and application of automatic electrothermal digestion instrument —— a new pretreatment technology for detection of arsenic in urine samples

Abstract

Objective \nTo explore the application of new pretreatment technology of automatic electrothermal digestion instrument in the detection of arsenic in urine samples, in order to achieve rapid, convenient and accurate detection results. \n \n \nMethods \nUsing wet digestion, an advanced sample preparation and digestion method (referred to as new pretreatment technology) was established by hydride generation-atomic fluorescence spectrometry (HG-AFS). Wet digestion: took 1.0 ml urine samples and put them into 10.0 ml corked scale digestive tubes, and added 0.20 ml sulfuric acid, 0.30 ml nitric acid and 0.50 ml hydrogen peroxide into the tubes successively. Shook solution and put them at AED-IV automatic electrothermal digestion instrument with 160 ℃ for half an hour, then heated up to 200 ℃ for 1 hour. It needed to be continually heated up to 260 ℃ and dissolved the solution until colorless transparent or light yellow. When the liquid level calm, and uniform reflux appeared, which meant the digestion finished, and then measured by atomic fluorescence photometer. At the same time, the new pretreatment technology was compared with the current standard (WS/T 474-2015) method, and the standard curve and linear range were calculated, as well as the detection line, precision and accuracy of the sample measurement. \n \n \nResults \nThe new pretreatment technology could digest 60 samples per sample, which was superior to the current standard methods (20 samples) and reduced the amount of reagent used. There was no statistically significant difference between the two methods (P > 0.05). In the linear range of 0-100 μg/L, the correlation coefficient (r) > 0.999 3, the detection limit of the method was 0.066 μg/L, and the relative standard deviation (RSD) < 5%. \n \n \nConclusions \nThe new pretreatment technology is fast, efficient, environmentally friendly, economical, highly automated. The experimental result error is in a controllable range. It can be used for digestion of arsenic content in urine of different concentrations and has high applicability. \n \n \nKey words: \nUrine;\xa0Arsenic;\xa0AED-IV automatic electrothermal digestion instrument