湿式消化-ICP-AES法测定航空润滑油中镍钛镁铬钼锡

研究采用硝酸-高氯酸混合酸湿式消化法，建立ICP-AES法同时测定航空润滑油中痕量金属元素镍、钛、镁、铬、钼、锡。样品消化完全、快速，检出限分别为(μg．L^-1)：镍4．1、钛2．1、镁4．2、铬3．2、钼3．6、锡24．4，RSD小于5％，回收率为96．0％～104．0％。

ICP-AES DETERMINATION OF NICKEL,TITANIUM, MAGNESIUM,CHROMIUM,MOLYBDENUM AND STANNUM IN AVIATION LUBRICATING OIL BY WET DIGESTION OF SAMPLES

Conditions of wet digestion of the oil samples with acid mixture were studied, and the process of repeated digestion of 1~2 g of sample with conc. HNO_3 and finally fuming with mixed acid of HNO_3 and HClO_4((3+1)) was chosen for the pretreatment of oil sample. A slightly yellow or colorless solution was obtained and transferred to a 25 mL volumetric flask and diluted to mark with water, which was used as the mother solution for the ICP-AES determination. By this wet-digestion treatment, the organic matters were completely oxidized and decomposed, thus, eliminating the matrix interference effectively. The optimum working conditions of the ICP-AES determination of the above mentioned metal ions were described in detail. The values of detection limit (3S_b/K) of the six element were found to be (gL~(-1)): Ni 4.1, Ti 2.1, Mg 4.2, Cr 3.2, Mo 3.6 and Sn 24.4. Recoveries obtained by standard addition method were in the range of 96.0% to 104.0%. RSDs found for these elements in analysis of oil sample were less than 5%.