Assisted Dispersive Solid Phase Microextraction Research Articles

Ultrasound assisted dispersive solid phase microextraction using polystyrene-polyoleic acid graft copolymer for determination of Sb(III) in various bottled beverages by HGAAS

A new polyoleic acid-polystyrene (PoleS) block/graft copolymer was synthesized and applied as adsorbent for ultrasound assisted dispersive solid phase microextraction (UA-DSPME) of Sb(III) in different bottled beverages and analysis using hydride generation atomic absorption spectrometry (HGAAS). Adsorption capacity of the PoleS was 150 mg g−1. Several sample preparation parameters such as sorbent amount, solvent type, pH, sample volume and shaking time were optimized (based on central composite design (CCD) approach) and evaluated in respect to the recovery of Sb(III). The method revealed a high tolerance limit of matrix ions presence. Under optimized conditions, linearity range, the limit of detection, the limit of quantitation, extraction recovery, enhancement factor, preconcentration factor were 5–800 ng L−1, 1.5 ng L−1, 5.0 ng L−1, 96%, 82, 90, respectively. Accuracy of the UA-DSPME method was confirmed based on different certified reference materials and standard addition method. Factorial design was utilized to estimate the influences of variables of recovery of Sb(III).

Cellulose-based nanocomposite for ultrasonic assisted dispersive solid phase microextraction of triazole fungicides from water, fruits, and vegetables samples

Herein, an ultrasound-assisted dispersive solid phase microextraction (UA-DSPME) approach has been described for trace level analysis of triazole fungicides in real samples. For this purpose, a new nanosorbent was prepared through modification of carboxymethylcellulose biopolymer with zinc-based metal–organic framework and graphene oxide, and fully characterized. Then, the effect of extraction parameters on extraction efficiency was optimized for the microextraction process. Finally, desorbed triazole fungicides with ethanol were determined using gas chromatography equipped with flame ionization detector. This technique provided good linearity (R2 > 0.99), low detection limits (0.3–1.5 ng mL−1), high preconcentration factors (419–426), good relative recoveries (91.6–102 %), and high repeatability (RSD < 4.1 %) at optimized conditions (amount of sorbent: 15 mg; pH of solution: 7.0; and extraction time; 4 min). Ultimately, this approach was applied to determine triazole fungicides in different water and food samples.

Ultrasound assisted dispersive solid phase microextraction of inorganic arsenic from food and water samples using CdS nanoflowers combined with ICP-OES determination

Direct determination of arsenic species in real samples is challenging due to their trace concentration and spectral interferences by coexisting ions. Herein, we proposed an ultrasound-assisted dispersive solid phase microextraction (DSPME) procedure for the analyses of the trace inorganic arsenic. The hydrothermally synthesized cadmium sulfide nanoparticles (CdS NPs) completely adsorbed both arsenic species within 20 s at the initial arsenic concentration of 100 µg L−1. The detection limit (3 S/m) of the proposed method was found to be 0.5 ± 0.2 and 0.8 ± 0.2 ng L−1 for As(III) and As(V), respectively. The accuracy of the method against the systematic and constant errors was confirmed by the analysis of the Standard Reference Material (SRM) (>95% recovery with <5% RSD). The Student’s t-test values were found to be less than the critical Student’s t value at a 95% confidence level. The method was successfully employed for the determination of arsenic in food samples.

Ultrasound Assisted Dispersive Solid Phase Microextraction of Thymol and Carvacrol in Pharmaceutical Products Using Graphene Oxide as an Adsorbent Prior to Analysis by High Performance Liquid Chromatography

Background: Thymol and carvacrol are the most important dietary constituents in thyme species. These two active compounds are used for the standardization of pharmaceutical compounds. Objective: In this work, a simple and reliable ultrasonic assisted dispersive solid phase microextraction method (USA-DSPME) coupled with high performance liquid chromatography-ultra violet detection system was developed to determine thymol and carvacrol in pharmaceutical syrups. The efficiency of SPME sorbent was examined through several sorbents and finally Graphene Oxide (GO) was applied for extraction of the analytes. Method: The efficiency of GO was compared with three reduced forms of GO adsorbents as well. Several effective factors on the extraction performance were investigated. Results: Under the optimized conditions for the GO sorbent, inter and intra-day relative standard deviations (RSDs, n = 3) and the Limits of Detections (LODs) were lower than 5.0% and 0.02 μg/ml, respectively. Moreover, good linear ranges were observed in wide concentration ranges with R-squared larger than 0.9961 for both thymol and carvacrol. Conclusion: The present method is reliable and simple for determination of carvacrol and thymol in pharmaceutical products.

Synthesis, modification, characterization and application of AC@Fe 2 O 3 @MnO 2 composite for ultrasound assisted dispersive solid phase microextraction of refractory metals in environmental samples

Activated carbon-coated iron oxide @ manganese oxide nanoparticles ([email protected]2O3@MnO2) were synthesized by sol-gel method. Activated carbons (AC) were prepared from tyres after carbonization at 900 °C and chemically activated using H2O2. The composite was characterized by scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscope (TEM), X-ray powder diffraction (XRD), nitrogen adsorption and FTIR. The Fourier Transform Infrared (FTIR) confirmed the presence of carboxyl and hydroxyl groups on the surface of AC. In addition, the TEM, SEM/EDS and XRD revealed attractive properties of the composite which further confirmed the union of metal oxide nanoparticles with the surface of AC. The composite was used as an adsorbent for ultrasound assisted dispersive solid phase microextraction (UA-DSPME) of Ge, Hf, Mo, Nb, Sb, Ta, Te, Sn, Ti, W and Zr in environmental water samples. Under optimized conditions, the limits of detection and quantification ranged 0.0004–0.02 μg L−1 and 0.001–0.07 μg L−1, respectively. The precisions expressed in terms of the relative standard deviation (%RSD) were less than or equal to 5.2%. The developed adsorbent was applied in real water samples. The results obtained by the developed method were not statistically different with those obtained by the reference method.