ABSTRACT Sample preparation procedures are essential for drug analysis in biological fluids, tissues, pharmaceutical preparations, food and environmental matrices. For this purpose different techniques have been used like protein precipitation, liquid liquid extraction (LLE) and solid phase extraction (SPE). Magnetic solid phase extraction (MSPE) has become a highly preferred method due to its advantages as a sample preparation-pretreatment technique when compared to classical methods as a novel type of SPE. Basically, this type of extraction is based on the separation of different analytes from complex matrices based on the use of magnetic nanoparticles (MNPs) as adsorbents. Magnetic solid phase extraction minimizes the use of additional steps which reduces the manipulation of conventional extractions. The main advantages depend on its simplicity, environmentally friendly process, disposable cost, reduced solvent consumption, and short duration. In this review, special attention is paid on drug analysis by using MSPE prior to various analytical methods from biological, environmental and food matrices. MSPE applications, with various types of magnetic adsorbents, and different analytical method combinations were revealed for drug analysis.

ABSTRACT Objective: The main goal of this study was to compare the polymerization degree of bulk-fill giomer resin cured with three different light-curing units (LCUs): a polywave third-generation (Valo); a monowave (DemiUltra: DU); and a second-generation LED (Optima 10: Opt) LCUs by using structural and mechanical properties. Material and methods: Giomer samples of 2 and 4 mm cured with three LCUs were employed in vitro analysis. The degree of curing (DC%) was determined with Fourier-Transform Infrared Spectroscopy (FTIR). Microstructural features were observed with scanning electron microscopy (SEM). Flexural strength (FS), compression strength (CS), elastic modulus and fracturing strain were determined for mechanical properties. Surface microhardness (SMH) values were also measured. Oneway ANOVA, two-way analysis of variance and Tukey multiple comparison tests were used for statistically analyzing the FS and SMH. Results: DC% values were 58.2, 47.6, and 39.7 for the 2 mm samples cured with DU, Opt., and Valo LCUs, respectively. DC% values of the 4 mm samples were 50.4, 44.6, and 38.2 for DU, Opt, and Valo, respectively. SMH values were Valo, Opt<DU at top of the samples; Valo<DU, Opt at 2 mm, and DU, Valo<Opt at 4 mm depth. Giomer samples cured with Opt and DU exhibited higher FS values than Valo. CS values were similar but compressive modulus and fracturing strain (%) varied depending on the curing protocol. Conclusions: Based on the results, it can be concluded that curing device and protocol strongly affect crosslinking reactions and thus DC%, SMH, compressive modulus and strain at break values. Consequently, it can be deduced that curing protocol is possibly the most important parameter for microstructure formation of highly-filled composite restoratives because it may bring some structural defects and physical frailties on restorations due to lower degree of polymerization.

A simple analytical procedure, magnetic solid phase extraction combination to HPLC, has been developed for the analysis of gemifloxacin in human plasma and breast milk. Before chromatographic separation, magnetic solid phase extraction has been applied for sample preparation which is currently preffered extraction technique accordingly its simple, fast and efficient procedure. Fe3O4 magnetic nanoparticles have been used as magnetic adsorbents, the adsorption process has been optimized. RP C18 column has been used with mobile phase composed of acetonitrile-10 mM orthophosphoric acid including 1 mL/L triethylamine (60:40) by isocratic elution with flow rate of 1.3 mL/min. Calibration curve is linear over the range of 0.5-30 μg/mL and 0.5-20 μg/mL for plasma and breast milk, respectively. LOD and LOQ has been found to be 0.15 and 0.5 μg/mL for both matrices. Intraday and interday RSD values are less than 3.57% for both assays. Moreover, the newly developed method provides fast, simple, cost reduced and sensitive assay for gemifloxacin.