Application of narrow-bore tube / dispersive liquid–liquid microextraction for extraction of BTEX from juice samples before their GC/FID determination

A new simple and effective method based on dispersive liquid–liquid microextraction (DLLME) procedure is proposed for rapid and simultaneous separation andpreconcentration of ultra trace amounts of benzene, toluene, ethylbenzene and xylene (BTEX) in juice samples. The DLLME method was performed in a narrow-bore tubecontaining aqueous sample. This simple configuration avoids the centrifugation step, which is time consumingstep in the extraction and permits a solvent with a density lighter than water to be used as extraction solvent and therefore expands the applicability of DLLME to a widerrange of solvents. The influence of extraction parameters, such as kind and volume of extraction and disperser solvents, volume of sample, temperature and pH of the solution and its ionic strength were investigated and optimized. The best efficiency of extraction acquired usingacetone and nonanol as dispersive and extraction solvents respectively. Under the optimum condition, the proposedmethod provided a wide linear range (6–700 μg.L−1) withcorrelation coefficient (R2) of 0.96, reproducibility (asRSD) better than 4.5% (n= 5) and relative recovery of 96.2- 101.0%. The limit of detection (S/N=3) and enrichment factor were in the range of 1.5–2.2 μg.L−1 and 31–173 times, respectively. At the end, the DLLME-GC–FID method was successfully applied for the determination of BTEX compounds in a few real juice samples.

کلیدواژه ها:

Narrow-bore tube dispersive liquid–liquid microextraction ، Juice samples ، BTEX ، GC-FID