3.2.4. Effect of type of dilution solvent
Considering the demand of sampling volume for the determination by the conventional spectrophotometer, 3mL volume of sample was needed for detection. As one of the miniaturized sample pre-treatment method, the volume of the resultant sample was micro. To realize the hyphenation, the proper dilution was necessary, which would affect the ratio of volumes between water phase and organic phase thus led to poor enhancement factors. In the experiment, some conventional solvents including methanol, ethanol, acetone, acetonitrile were investigated. The results indicated that acetone was the best dilution solvents for the determination of Cd. During the determination, it was found that acetone had an obvious sensitization to the spectrophotometric determination, which contributed to the high sensitivity and EF, as illustrated in our previous work[20]. During the optimization, lower concentration of Cd (25ngL−1)was used and the absorbance signal was still at a high level