Determination of teicoplanin in human plasma by reverse micelle mediated dispersive liquid-liquid microextraction with high performance liquid chromatography

A reverse micelle-mediated dispersive liquid-liquid microextraction coupled to high-performance liquid chromatography for the simultaneous determination of agomelatine and venlafaxine in pharmaceuticals and human plasma

An eco-friendly dispersive liquid-liquid microextraction mediated with a reverse micelle and coupled to an HPLC-DAD was developed for the simultaneous determination of venlafaxine and agomelatine in dosage forms and human plasma. All the parameters affecting the extraction efficiencies of both drugs were investigated and optimized. Under the optimal conditions, an effective analytes' preconcentration with enrichment factors (EFs) up to 72 was achieved. The linearity of the method was established over the concentration range of 0.50-70.0 and 3.0-100.0 ng/mL for venlafaxine and agomelatine, respectively with good correlation coefficients > 0.998. The method exhibited low detection limits in the range of 0.15-0.89 ng/mL and excellent precisions expressed in %RSD < 3% with average recoveries between 95.0 to 101.0%. The proposed method was employed to analyze the targeted analytes in dosage forms and human plasma samples with favorable characteristics like excellent enrichment, high sensitivity, great accuracy, and high precision. Finally, the greenness of the developed method was assessed using three distinct metric tools, confirming the greenness of the proposed method. The findings of this research could have more general implications for the extraction of other analytes from various matrices.

A tool to assess analytical sample preparation procedures: Sample preparation metric of sustainability

Sample preparation is a key step in most analytical methods, generally regarded as the least green step of the entire procedure. The existing green metrics assess the greenness of sample preparation techniques through the evaluation of the whole analytical procedure: including sampling, sample preparation, and the final detection/quantitation. Such inclusion of the entire method makes assessing the sustainability of a newly developed sample preparation technique quite challenging, as many aspects not solely linked to the sample preparation step are unavoidably considered. Thus, an alternative metric that can explicitly and exclusively evaluate the sample preparation is proposed. The metric is simple; it reports the result with a clock-like diagram, displaying the greenness outcome of main sample preparation parameters and a total score. This new metric can differentiate closely related microextraction approaches in terms of sustainability. The metric is also open-source and can be used by downloading the Excel sheet provided.

Determination of atypical antipsychotics in human plasma by UPLC-UV with polystyrene nanofibers as a solid-phase extraction sorbent

A novel extraction procedure was developed using polystyrene (PS) nanofibers as a solid-phase extraction sorbent to collect atypical antipsychotics (AAPs) from human plasma. The extraction targets were then monitored by ultra high performance liquid chromatography with an ultraviolet detector system. Parameters affecting extraction efficiency such as fiber packing amount, wash solution, and eluted solvent were investigated. Under optimized conditions, the linear range of seven AAPs was 1-50 μgmL-1 (R 2 > 0.996). Inter-day and intra-day relative standard deviations were less than 15.1%, and relative error varied from -17.1% to 12.0%. Furthermore, 50.5-79.3% extraction recoveries were obtained. The lower limit of quantification was 1 μg mL-1, and detection limit was 0.5 μg mL-1. The method developed in this study may be applied to simultaneous quantification of seven AAPs in human plasma due to its simplicity, selectivity, and efficiency.