Larki Arash, Nasrabadi Mehdi Rahimi, Pourreza Nahid
Marine Science Research Institute, Khoramshahr University of Marine Science and Technology, Khoramshahr, Iran.
Department of Chemistry, Imam Hossein University, Tehran, Iran; Nano-Science Center, Imam Hossein University, Tehran, Iran.
Forensic Sci Int. 2015 Jun;251:77-82. doi: 10.1016/j.forsciint.2015.03.019. Epub 2015 Mar 28.
In the present study, a simple, fast and inexpensive method based on dispersive liquid-liquid microextraction (DLLME) prior to microvolume UV-vis spectrophotometry was developed for the preconcentration and determination of trinitrotoluene (TNT). The procedure is based on the color reaction of TNT in alkaline medium and extraction into CCl4 as an ion pair assisted by trioctylmethylammonium chloride, which also acts as a disperser agent. Experimental parameters affecting the DLLME method such as pH, concentration of sodium hydroxide, amount of trioctylmethylammonium chloride, type and volume of extraction solvent were investigated and optimized. Under the optimum conditions, the limit of detection (LOD) was 0.9ng/mL and the calibration curve was linear in the range of 3-200ng/mL. The relative standard deviation for 25 and 100ng/mL of TNT were 3.7% and 1.5% (n=6), respectively. The developed DLLME method was applied for the determination of TNT in different water and soil samples.
在本研究中，开发了一种基于分散液液微萃取（DLLME）的简单、快速且廉价的方法，用于在微量紫外可见分光光度法之前对三硝基甲苯（TNT）进行预浓缩和测定。该方法基于TNT在碱性介质中的显色反应，并在氯化三辛基甲基铵的辅助下作为离子对萃取到四氯化碳中，氯化三辛基甲基铵同时也作为分散剂。研究并优化了影响DLLME方法的实验参数，如pH值、氢氧化钠浓度、氯化三辛基甲基铵用量、萃取溶剂的类型和体积。在最佳条件下，检测限（LOD）为0.9ng/mL，校准曲线在3-200ng/mL范围内呈线性。25ng/mL和100ng/mL TNT的相对标准偏差分别为3.7%和1.5%（n=6）。所开发的DLLME方法应用于不同水样和土壤样品中TNT的测定。
