Determination of Calcium in Cigarette Paper by Continuous Flow Analysis Method with Ultrasonic Extraction

A method for determination of calcium in cigarette paper by continuous flow analysis method with ultrasonic extraction was established. The cigarette paper sample (treated to 2 mm×2 mm) of 0.1 g was extracted with ultrasonic in 100 mL of 0.050 mol·L^-1 nitric acid solution for 30 min, and the resulting solution was filtered. Based on the principle that Ca²⁺ reacted with DBC-arsenazo in a certain alkaline medium and the blue complex obtained could be used for determination of calcium, the filtrate was determined by continuous flow analyzer with 1.0 g·L^-1 DBC-arsenazo solution as the chromogenic reagent under the condition of buffer solution at pH 11, and the detection wavelength was 630 nm. As shown by the results, the linear range of the standard curve of calcium was 40-200 mg·L^-1, with detection limit (3s) of 1.02 mg·L^-1. The method was used for sample analysis, giving the results of RSDs (n=6) of the determined values less than 2.0%. Test for recovery was made by standard addition method, giving values of recovery in the range of 96.1%-102%. The proposed method was compared with YC/T 274-2008, and P value obtained by t-test was above 0.05. There was no significant difference between the two methods.