Hollow Fiber Solid Phase Microextraction Research Articles

Fabrication of a novel nanocomposite based on sol–gel process for hollow fiber-solid phase microextraction of aflatoxins: B 1 and B 2, in cereals combined with high performane liquid chromatography–diode array detection

The new pre-concentration technique, hollow fiber-solid phase microextraction based on carbon nanotube reinforced sol–gel and liquid chromatography–photodiode array detection was applied to determination of aflatoxins B 1, B 2 (AFB 1, AFB 2) in rice, peanut and wheat samples. This research provides an overview of trends related to synthesis of solid phase microextraction (SPME) sorbnents that improves the assay of aflatoxins as the semi-polar compounds in several real samples. It mainly includes summary and a list of the results for a simple carbon nanotube reinforced sol–gel in-fiber device. This device was used for extraction, pre-concentration and determination of aflatoxins B1, B2 in real samples. In this technique carbon nanotube reinforced sol was prepared by the sol–gel method via the reaction of phenyl trimethoxysilane (PTMS) with a basic catalyst (tris hydroxymethyl aminomethan). The influences of microextraction parameters such as pH, ageing time, carbon nanotube contents, desorption conditions, desorption solvent and agitation speed were investigated. Optimal HPLC conditions were: C 18 reversed phase column for separation, water–acetonitril–methanol (35:10:55) as the mobile phase and maximum wavelength for detection was 370 nm. The method was evaluated statistically and under optimized conditions, the detection limits for the analytes were 0.074 and 0.061 ng/mL for B1 and B2 respectively. Limit of quantification for B1 and B2 was 0.1 ng/mL too ( n = 7). The precisions were in the range of 2.829–2.976% ( n = 3), and linear ranges were within 0.1 and 400 ng/mL. The method was successfully applied to the analysis of cereals (peanut, wheat, rice) with the relative recoveries from 47.43% to 106.83%.

Fabrication of a novel nanocomposite based on sol–gel process for hollow fiber-solid phase microextraction of Atnelol in biological samples combined with HPLC-DAD determination

Fabrication of a novel nanocomposite based on sol–gel process for hollow fiber-solid phase microextraction of Atnelol in biological samples combined with HPLC-DAD determination

Optimization of a novel method for determination of benzene, toluene, ethylbenzene, and xylenes in hair and waste water samples by carbon nanotubes reinforced sol–gel based hollow fiber solid phase microextraction and gas chromatography using factorial experimental design

A novel design of solid phase microextraction fiber containing carbon nanotube reinforced sol–gel which was protected by polypropylene hollow fiber (HF-SPME) was developed for pre-concentration and determination of BTEX in environmental waste water and human hair samples. The method validation was included and satisfying results with high pre-concentration factors were obtained. In the present study orthogonal array experimental design (OAD) procedure with OA 16 (4 4) matrix was applied to study the effect of four factors influencing the HF-SPME method efficiency: stirring speed, volume of adsorption organic solvent, extraction and desorption time of the sample solution, by which the effect of each factor was estimated using individual contributions as response functions in the screening process. Analysis of variance (ANOVA) was employed for estimating the main significant factors and their percentage contributions in extraction. Calibration curves were plotted using ten spiking levels of BTEX in the concentration ranges of 0.02–30,000 ng/mL with correlation coefficients ( r) 0.989–0.9991 for analytes. Under the optimized extraction conditions, the method showed good linearity (0.3–20,000 ng/L), repeatability, low limits of detections (0.49–0.7 ng/L) and excellent pre-concentration factors (185–1872). The best conditions which were estimated then applied for the analysis of BTEX compounds in the real samples.

Simultaneous extraction and determination of lead, cadmium and copper in rice samples by a new pre-concentration technique: Hollow fiber solid phase microextraction combined with differential pulse anodic stripping voltammetry

In the present work, a novel solid phase microextraction (SPME) technique using a hollow fiber-supported sol–gel combined with multi-walled carbon nanotubes, coupled with differential pulse anodic stripping voltammetry (DPASV) was employed in the simultaneous extraction and determination of lead, cadmium and copper in rice. In this technique, an innovative solid sorbent containing mixture of carbon nanotube and a composite microporous compound was developed by the sol–gel method via the reaction of tetraethylorthosilicate (TEOS) with 2-amino-2-hydroxymethyl-propane-1,3-diol (TRIS). The growth process was initiated in basic condition (pH 10–11). Afterward this sol was injected into a polypropylene hollow fiber segment for in situ gelation process. The main factors influencing the pre-concentration and extraction of the metal ions; pH of the aqueous feed solution, extraction time, aqueous feed volume, agitation speed, the role of carbon nanotube reinforcement (as-grown and functionalized MWCNT) and salting effect have been examined in detail. Under the optimized conditions, linear calibration curves were established for the concentration of Cd(II), Pb(II) and Cu(II) in the range of 0.05–500, 0.05–500 and 0.01–100 ng mL −1, respectively. Detection limits obtained in this way are, 0.01, 0.025 and 0.0073 ng mL −1 for Cd(II), Pb(II) and Cu(II), respectively. The relative standard deviations (RSDs) were found to be less than 5% ( n = 5, conc.: 1.0 ng mL −1).