Liquid Chromatographic Determination of 1,3,5-Trinitroperhydro-1,3,5-triazine and 2,4,6-Trinitrotoluene in Human Plasma and Groundwater Samples Utilizing Microextraction in Packed Syringe

A rapid and efficient analytical method suitable for the simultaneous determination of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 2,4,6-trinitrotoluene (TNT) in groundwater and human plasma samples using liquid chromatography with UV detection (LC-UV) has been developed. RDX and TNT were baseline separated within time span of 4.8 min on a reverse phase C-18 analytical column with water acetonitrile mixture in ratio 30:70 (v/v) as mobile phase. The UV detection was carried out at 234 nm. A sample preparation method for biological and environmental matrices using microextraction by packed sorbent (MEPS) technique has been implemented, employing 4 mg of C-18 silica sorbent inserted into a microvolume syringe and using only 30 mu L of plasma and groundwater samples. Several factors affecting the performance of MEPS, such as number of extraction cycles, washing solvent volume, elution solvent volume and carryover etc., were optimized. Limits of detection were 0.0997 and 0.0628 ng mL(-1) for RDX and TNT, respectively. The extraction yields were satisfactory for both analytes (> 81.2 %) as well as the precision data, which were always in the low percentage of relative standard deviation values (< 5.6 % , n = 6). The present method is miniaturized, fully automated, and robust which can be easily used for forensic studies of explosives in environmental and biological samples.