چكيده
Abstract
CMK-1 typed ordered nanoporous carbon was investigated as a novel solid phase
microextraction fiber for the first time. The structural order and textural properties of
the prepared materials were studied by XRD, SEM and nitrogen adsorption. The
microextraction process was coupled with GC-FID and used to extract BTEX and
MNT from the head space of the solution samples. Prepared fibers featured
advantages like easy and fast preparation together with high thermal and mechanical
resistance which a fiber could be used for more than 60 tests.
Using the Taguchi method, an orthogonal array design (OAD), OA16 (45) was
employed to optimize the HS-SPME of BTEX and BTEX. Five relevant factors, i.e.
sample volume, stirring rate, ionic strength, extraction time and temperature were
selected and the effects of each factor were studied at four levels on the extraction
efficiency of BTEX and MNT compounds and optimized. Based on the results
obtained from the analysis of variance (ANOVA), the optimum conditions for
extraction BTEX were established as: 12 ml sample volume; vial temperature :
laboratory temperature; 8 % (w/v) NaCl ; 30 min extraction time and stirring rate of
1200rpm. Based on the results obtained from the analysis of variance (ANOVA), the
optimum conditions for extraction MNT were established as: 12 ml sample volume;
60°C; 8 % (w/v) NaCl ; 30 min extraction time and stirring rate of 600rpm.Under the
optimized conditions and for all BTEX components, the linearity was from 3 to 800
μg L−1, the relative standard deviation (RSD%) of the method was between 4.21 and
9.37% and limit of detections (LODs)were between 0.27 and 1.1 μg L−1.The recovery
values were from 87.1% to 106.25% in water samples. Under the optimized
conditions and for all MNT components, the linearity was from 0.5 to 400 μg L−1, the
relative standard deviation (RSD%) of the method was between 3.75 and 4.25% and
limit of detections (LODs) were between 0.01 and 0.16 μg L−1.The recovery values
were from 89.6% to 108.8% in water samples. Finally, the applicability of the
proposed method was evaluated by the extraction and determination of BTEX in the
real water samples and petrochemical samples.
