In this study, a green ionic-liquid based vortex-synchronized matrix solid-phase dispersion (VS-MSPD) combined with high performance liquid chromatography (HPLC) method was developed as a quantitative determination method for four anthraquinones in Cassiae Semen. Two conventional adsorbents, C18 and silica gel were investigated. The strategy included two steps: Extraction and determination. Wasted crab shells were used as an alternative adsorbent and ionic liquid was used as an alternative solvent in the first step. Factors affecting extraction efficiency were optimized: A sample/adsorbent ratio of 2:1, a grinding time of 3 min, a vortex time of 3 min, and ionic liquid ([Domim]HSO4, 250 mM) was used as eluent in the VS-MSPD procedure. As a result, the established method provided satisfactory linearity (R > 0.999), good accuracy and high reproducibility (RSD < 4.60%), and it exhibited the advantages of smaller sample amounts, shorter extraction time, less volume of elution solvent, and was much more environmental-friendly when compared with other conventional methods.

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A novel on‐line synergistic proconcentration strategy coupling field‐amplified sample stacking and micelle to cyclodextrin stacking for cationic analytes in capillary zone electrophoresis has been proposed and applied for the separation and determination of two alkaloids, matrine, and oxymatrine in complicated matrix samples. The approach was performed by the long injection of sample in a low‐conductivity sodium dodecyl benzene sulfonate solution followed by the injection of hydroxypropyl‐β‐cyclodextrin solution in higher conductivity. The stacking mechanism of this method has been expounded and parameters affecting stacking effect have been optimized in our study. Under the optimum experimental conditions, 169‐ and 218‐fold sensitivity improvements were achieved for matrine and oxymatrine when compared with normal injection. Analytical indicators including linearity, limits of detection, and reproducibility (intra‐ and inter‐day relative standard deviations) were evaluated. Moreover, sample matrix effect was studied using compound flavescent sophora and salicylic acid powder and spiked urine samples. The developed method is an attempt for the combination of micelle to cyclodextrin stacking with other stacking methods. It could be a good alternative choice for the determination of alkaloids in a complex sample matrix.

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A simple, convenient, and sensitive method that involves combining matrix solid-phase dispersion extraction with field-amplified sample stacking in capillary electrophoresis has been developed for the determination of organic acids in a complex solid matrix. Mesoporous molecular sieve, MCM-48, was synthesized by a hydrothermal method and selected as the adsorbent in matrix solid-phase dispersion. After fast extraction, the enriched analytes were back-extracted into a basic aqueous solution for field-amplified sample stacking in capillary electrophoresis. Parameters that affect extraction efficiency and sample stacking were optimized. Under the optimal conditions, approximately 42-, 49-, and 56-fold sensitivity enhancements were achieved for danshensu, protocatechuic acid, and cinnamic acid, respectively, when compared to normal injection. A satisfactory correlation coefficient (r > 0.99) was obtained. Both intra- and interday precision were lower than 2.53%. And the limits of detection of the three organic acids ranged between 0.01 and 0.029 μg/mL. Finally, the newly proposed method was successfully applied to the determination of organic acids in Fufang Danshen tablets, which indicates its great potential in analyzing organic acids in a complex matrix.