| A new ferrofluid prepared from toner powder and deep eutectic solvent was used in air-assisted liquid-liquid
microextraction procedure for extraction of sixteen polycyclic aromatic hydrocarbons from urine and saliva
samples of tobacco smokers. In this work, initially, a water-immiscible deep eutectic solvent is synthesized by
mixing choline chloride and stearic acid under mild conditions and used as a support solvent in the preparation
of ferrofluid from toner powder. Then, a few microliters of the prepared ferrofluid is mixed with sample solution
and dispersed in all parts of the solution by performing aspirating/dispersing cycles. To collect the ferrofluid, a
magnet is deposited at the outside of the tube and the solution is discarded. The analytes in the collected phase
are back-extracted into n-heptane and determined by gas chromatography–mass spectrometry. The validation
parameters including limit of detection and quantifcation, stability, accuracy, linearity, selectivity, precision,
enrichment factor, and extraction recovery were studied and the data showed that the method have low limits of
detection (in the range of 6–21 ng L−1 in deionized water and 18–63 ng L−1 in saliva and urine samples,
respectively) and quantifcation (in the range of 20–72 ng L−1 in deionized water and 60–216 ng L−1 in saliva
and urine samples). Extraction recoveries and enrichment factors ranged from 61 to 84% and 305 to 420,
respectively. Relative standard deviations of ≤9% for the extraction of 200 ng L−1of each analyte were obtained
for intra– (n = 6) and inter–day (n = 6) precisions. Finally, urine and saliva samples of tobacco smokers were
successfully analyzed using the proposed method. |