New Approach for Detection of Ultra Trace Amounts of Organic Compounds as Markers of Predict to Exploration of Petroleum Reservoir by Cloud Point Extraction Combined with UV-VIS Spectrophotometry and GC-MS Techniques

This work is an attempt to use what is to recognize the leakage of hydrocarbons as Dienzothiophene (DBT) and N-Ethylcarbazole (CARB) from petroleum reservoir from depth to surface so as to the possibility of using such a phenomenon as proximity indicator for petroleum deposits. The soil and water samples near of a productive oil wells (Maysan- Iraq) were chosen as a case study. The ultra trace quantities of these hydrocarbon compounds that constitute organic extracted were determined by cloud point extraction (CPE) combined with UV-VIS and GC-MS techniques. The optimization of conditions of CPE was conducted with UV-VIS and using Triton 114 (TX 114) as non-ionic surfactants. These conditions were of 0.4-0.6 mL of TX-114, equilibration temperature of 65 ?C , incubation time of 20 min and 0.5 M LiCl chosen as the best electrolyte for CPE. The conditions and statistical analysis of measurement by UV-VIS and GC-MASS techniques to DBT and CARB are ?max at 231 and 237nm, concentration range of Beer's law was (0.3-3, ?g mL-1), molar absorptivity of 5.9892x104 and 5.6523x104 L mol-1 cm-1, LOD values were of 0.0021 and 0.251 ?g mL-1, and LOQ values were 0.00693 and 0.8283 ?g mL-1 respectively. The conditions of separation used for the determination of DBT and CARB by GC-MS were the same conditions of CPE- UV-VIS. The results indicated that the retention times were of 16.22 and17.88 min, concentration range of 0.01-2, 0.05-2 ?g mL-1) for DBT and CARB respectively. LOD value of DBT was 0.0074 ?g mL-1, while for CARB was 0.00388 ?g mL-1. Analysis of hydrocarbons compounds concentrations in organic extract showed that the amounts of these compounds were different. For example, the concentration of DBT in Maysan Governorate near Halfaya well (1000 m) was of 1.1953 ?g mL-1, while it has a value of 0.4802 ?g mL-1 at 750 m and 0.163 ?g mL-1 at 500 m. The experimental results of this study indicated that the analysis of hydrocarbons which extracted from soil and water samples can be used to predict or the Remote sensing for the presence of petroleum accumulation or indicator of pollution.