31 Advanced technologies THE EVALUATION OF DIFFERENT SORBENTS AND SOLVENT MIxTURES IN PAH SAMPLE PREPARATION FOR GC/GC-MS ANALYSIS Jelena S. Cvetković*, Violeta D. Mitić, Vesna P. Stankov Jovanović, Marija V. Dimitrijević, Gordana S. Stojanović University of Niš, Faculty of Sciences and Mathematics, Department of Chemistry, Niš, Serbia GC/GC-MS-analysis of polycyclic aromatic hydrocarbons (PAHs) in complex sam- ples requires a previous treatment of the samples. In order to establish the effects of sorbents/solvents on the overall accuracy of the method, dispersive solid phase extraction as a method for the sample preparation in PAHs determination is em- ployed using three different solvent mixtures and sorbents (PSA, C18 and PS-DVB). Recovery values are dependent on compound and sorbents. The highest mean recovery was recorded for cyclohexane/acetone-C18 combination (58.45%) which is satisfactory, with the values above 70% for naphthalene (76.05%), fuoranthene (80.22%), pyrene (111.99%) and benzo[g,h,i]perylene (71.77%). Similar recoveries were obtained for cyclohexane/acetone-PS-DVB (55.50%) and cyclohexane/ace- tone-PSA (55.30%). Cyclohexane/acetone gave the highest recovery values for all three sorbents, so this solvent mixture could be used in PAH extraction from various matrices. Though the obtained recovery values for the investigated sorbent/solvent combinations were not impressive, they might be a good basis for future researches since, as far as we know, PS-DVB was not used in dSPE sample preparation for GC/GC-MS analysis of PAHs. Keywords: PAH, GC/GC-MS, sample preparation, dSPE, sorbent Introduction Polycyclic aromatic hydrocarbons (PAH) are ubiqui- tous environmental contaminants. PAHs are weakly dis- solved in water and their solubility decreases with the increase of the number of aromatic rings. They can be divided to light and heavy PAHs. Light PAHs are those which have up to 4 fused benzene rings, while heavy PAHs are those with more than 4 fused benzene rings. Heavy PAHs persist in the environment because of the low volatility, resistance to leaching and recalcitrant na- ture. [1] International Agency for Research on Cancer (IARC) have classifed PAHs as carcinogenic. [2] Euro- pean Commission (EC) has placed 16 PAH compounds (Table 1) on the pollutants priority list because of the po- tential toxicity and the frequency of occurrence. [3] Sources of PAH can be natural (forest fres, volcanoes, plants, fungi and bacteria) and anthropogenic (electric power generation, petroleum industry/distribution, home heating, internal combustion engines/traffc and the pro- duction of coke). The contamination of the environment is mainly caused by anthropogenic processes. Polycyclic aromatic hydrocarbons are widespread and can be found in soil, air, water, and also in food and human tissues. [4,5] They are present in the environment due to incomplete combustion of organic matter. Emissions from traffc have been found to be the main outdoor source for the indoor PAH concentration at urban and suburban locations in many industrialized countries [6], while indoor air is mainly polluted from tobacco smoke [7]. PAHs reach soil and water from the atmospheric deposition, through the discharge of industrial and domestic sewage effuents and spillages of petroleum products. [8] PAH contamina- tion is of great concern since they have toxic, carcino- genic, teratogenic and mutagenic effects. [9] Because of their prevalence in the environment, food and other life segments and evidenced harmful effects, PAHs analysis is of great signifcance. However, the measurement of the PAH concentration requires com- plicated, time consuming and tedious analytical proce- dures, as a result of the sample complexity. The analysis may be comprised during several steps: sampling, PAH extraction, the cleanup process and instrumental analy- sis. Extraction methods explored over the years include: Soxhlet’s, ultrasonic, liquid-liquid, purge and trap, head- space, shaking, vortex, solid-phase, supercritical fuid extraction, solid-phase micro extraction (SPME), stir-bar sorptive extraction (SBSE), miniaturized solid-phase ex- traction (MSPE), liquid-phase micro extraction (LPME) and membrane-assisted solvent extraction techniques (MASE). [10] Clean-up methods for PAHs analysis in- clude solvent partitioning and chromatographic proce- (oRIGINAL SCIENTIFIC PAPER) UDC 543.51:547.6:66.061.3 *Author address: Jelena Cvetković, Faculty of Science and Mathematics, Department of Chemistry, University of Niš, Višegradska 33, 18000 Niš, Serbia E-mail: jelena.cvetkovic7@gmail.com The manuscript received: February, 24, 2016. Paper accepted: March, 24, 2016. 5(1) (2016) 31-38