用20 mL水超声提取2 g剪碎后的烟用接装纸样品30 min,分取8 mL提取液,加入200 mmol·L^-1二乙基二硫代氨基甲酸钠(螯合剂)溶液100 μL,在体系酸度为pH 6.0条件下,于45℃反应10 min。反应结束后,加入正十二醇(萃取剂)60 μL和甲醇(分散剂)100 μL,涡旋,离心,取上层有机相,用甲醇定容至0.5 mL,过滤至色谱瓶中待测。以ZORBAX SB-C₁₈色谱柱为固定相,以不同体积比的甲醇-水混合液为流动相进行梯度洗脱,分离后的目标物用二极管阵列检测器于258 nm进行检测。结果显示:Cr³⁺、Cr⁶⁺标准曲线的线性范围均为2.00~100.00 μg·L^-1,检出限(3S/N)分别为3,6 μg·kg^-1;对实际样品进行加标回收试验,Cr³⁺的回收率为90.7%~105%,测定值的相对标准偏差(RSD,n=7)为4.2%~7.3%,Cr⁶⁺的回收率为84.1%~106%,测定值的RSD (n=7)为4.5%~7.6%;Cr³⁺、Cr⁶⁺的富集因子分别为25.6和9.5;方法用于5份实际样品分析,其中4份样品中均检出Cr³⁺和Cr⁶⁺,并且Cr⁶⁺检出量均比Cr³⁺检出量高。

2 g of the sheared cigarette tipping paper sample was extracted ultrasonically with 20 mL of water for 30 min. An aliquot of 8 mL of the solution was taken, and 100 μL of 200 mmol·L^-1 sodium diethyldithiocarbamate (chelating agent) solution was added for reaction at 45℃ for 10 min under the system acidity of pH 6.0. After reaction, 60 μL of n-dodecyl alcohol (extractant) and 100 μL of methanol (dispersant) were added. After vortex and centrifugation, the upper organic phase was taken and made its volume up to 0.5 mL with methanol, then filtered into chromatographic bottle for testing. ZORBAX SB-C₁₈ column was used as stationary phase, and a mixture of methanol and water with different volume ratios was used as mobile phase for gradient elution. The separated target compounds were detected by diode-array detector at 258 nm. The results showed that the linear ranges of standard curves of Cr³⁺ and Cr⁶⁺ were 2.00-100.00 μg·L^-1, with detection limits (3S/N) of 3, 6 μg·kg^-1, respectively. Test for recovery was made on the actual sample by standard addition method, giving results in the ranges of 90.7%-105% for Cr³⁺ and 84.1%-106% for Cr⁶⁺, and RSDs (n=7) of the determined values were in the ranges of 4.2%-7.3% for Cr³⁺ and 4.5%-7.6% for Cr⁶⁺. The enrichment factors of Cr³⁺ and C⁶⁺ were 25.6 and 9.5, respectively. This method was applied to analysis of the 5 actual samples, and Cr³⁺ and Cr⁶⁺ were both detected in 4 samples, with the detection amounts of Cr⁶⁺ higher than those of Cr³⁺.