Simultaneous determination of naproxen and esomeprazole in beagle dog plasma by supercritical fluid chromatography-tandem mass spectrometry coupled with evaporation-free liquid-liquid extraction

Deduction of full factorial design of HPLC technique for the simultaneous analysis of meloxicam and esomeprazole in their laboratory prepared tablets

A reversed phase HPLC method with UV detection was designed for the first time for the simultaneous estimation of meloxicam and esomeprazole in their combined tablet dosage forms. Full factorial design was used for rapid optimization of the proposed method. Chromatographic separation was reached using isocratic elution on C18 column. The mobile phase was a mixture of methanol: acetonitrile: 0.05 M potassium dihydrogen phosphate buffer at pH 5, adjusted using phosphoric acid and/or NaOH when needed. The flow rate was 1 mL/min and the injection volume was 20 µL. The detection wavelength was 230 nm. The working ranges of the method were 5.0-100.0 and 10.0-100.0 µg/mL, LOD values were 0.8 and 1.8 µg/mL and LOQ values were 2.6 and 5.5 µg/mL for meloxicam and esomeprazole, respectively. The proposed method was successfully applied to their combined tablet dosage forms with acceptable % recoveries (100.4 - 100.7%) obtained. Four methods were used to evaluate the greenness of the proposed method, suggesting the acceptability of the greenness of the proposed method.

Supercritical Fluid Chromatography in Bioanalysis-A Review

In the last decade, the instrumentation improvements in supercritical fluid chromatography (SFC) and the hyphenation to mass spectrometry (MS), have increased the SFC acceptance between scientists, becoming today a valuable tool in analytical chemistry. The unique selectivity, short analysis times, low consumption of organic solvents, and the greener mobile phase, have contributed to expanding its applicability which has led to an increase in the number of publications especially in the bioanalysis area. This work reviews the advantages and main applications of SFC in bioanalysis during the last 5 years. Fundamental aspects concerning mobile phase composition, stationary phase, hyphenation to MS as well as matrix effect have been discussed. Finally, the most relevant applications have been summarized.

Progress of Pretreatment and Analytical Methods of Proton Pump Inhibitors: An Update since 2010

Proton pump inhibitors (PPIs) are the most commonly used medication for stomach secretion disorders. However, when it comes to safe, discreet pharmaceutical practice, widely recognized preparational and analytical method(s) for PPIs with sensitivity, selectivity, speed and high accuracy still remains underdeveloped. For this reason, this paper sets out to make a comprehensive review of the preparation and determination methods for PPIs based on multiple matrices since 2010. We have integrated newly-developed techniques (such as solid phase extraction, liquid phase micro-extraction, and solid phase micro-extraction) into conventional sample preparational methods. On the other hand, our analytical techniques include liquid chromatography, supercritical fluid chromatography, capillary electrophoresis, and employment of sensors. In addition, we have identified the pros and cons of each technique and have forecast their future developmental trends.

Combination of pipette tip solid phase extraction and high performance liquid chromatography for determination of plant growth regulators in food samples based on the electrospun covalent organic framework/polyacrylonitrile nanofiber as highly efficient sorbent

Facile and sensitive determination of plant growth regulators (PGRs) in food samples is important but still remains great challenge. Herein, a pipette tip solid phase extraction (PT-SPE) method was developed for fast and sensitively detecting PGRs. The PT-SPE adsorbent was prepared by integrating a novel covalent organic framework (COF) of schiff base network 3 (SNW-3) and polyacrylonitrile (PAN) through electrospinning. The SNW-3 can easily adsorb PGRs with high special affinity through electrovalent bands between the ammonium ions of SNW-3 and the carboxy groups of PGRs. The polymer of PAN acts as scaffold material for SNW-3, which can lower seepage pressure hence accelerates adsorption/desorption kinetics. By combination with HPLC-DAD, a satisfactory method was successfully developed for simultaneous determination of ten PGRs in watermelon. Good analytical performances were achieved with this proposed method, including good linearity (5-500 ng/mL) with high correlation coefficients (R ≥ 0.9981), low limits of detection (S/N = 3, 0.24-3.19 ng/mL) and limits of quantification (S/N = 10, 1.65-5.72 ng/mL), satisfactory precision (intra-day RSDs ≤ 2.7%, inter-day RSDs ≤ 3.7%), and high accuracy (recovery: 82.8-113.0%). The method developed in this study shows high potential for design of high target-affinity adsorbents for food sample preparing.