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A boron nitride nanosheet (BNNS)-assisted matrix solid-phase dispersion method was established to microextract alkaloids from medicinal plants. The target compounds were identified by high-performance liquid chromatography coupled with ultraviolet detection and ion mobility quadrupole time-of-flight mass spectrometry. During the experimental process, several important parameters, including the type of dispersant, the amount of dispersant, the grinding time, and the type of elution solvent, were optimized. Finally, the BNNSs were chosen as the best dispersant, and their microcosmic morphologies were identified by scanning electron microscopy and transmission electron microscopy. Because of the special property of BNNSs, the cost of this experiment was greatly reduced, especially in elution volume, sample amount (50 mg), and extraction time (2 min). Under the best conditions, 50 mg of sample powder was dispersed with 50 mg of BNNSs, the grinding time was 120 s, the mixed powder was eluted with 200 μL of methanol, and good linearity (r 2  > 0.9993) and satisfactory recoveries (80-100%) were obtained. The inter- and intraday precisions were acceptable, with RSDs lower than 2.01 and 4.84%, respectively. The limits of detection ranged from 2.54 to 15.00 ng/mL, and the limits of quantitation were 8.47 to 50.00 ng/mL. The proposed method was successfully applied for the determination of liensinine, isoliensinine, and neferine in lotus plumule., (© 2021 Wiley-VCH GmbH.)

A novel, green and efficient in-situ cloud point-reinforced ionic liquid-assisted mechanochemical extraction (IS-CPR-IL-MCE) technique coupled with ultrahigh performance liquid chromatography was established to simultaneously extract, concentrate and separate five alkaloids (including liensinine, isoliensinine, neferine, O-demethyl nuciferine and nuciferine) from lotus leaf. The parameters affecting the extraction efficiency of target analytes, such as the amount of IL, surfactant and salt, grinding time, pH, enrichment temperature and time were systematically studied and optimized by single-factor and multifactor experiments. The highest extraction yield of alkaloids was obtained by IS-CPR-IL-MCE under the following conditions: 0.23 g of 1-dodecyl-3-methylimidazolium bromide, 0.37 g of Triton X-100, 7.73 of pH, 5 min of milling time, 2.5 g of (NH 4) 2 SO 4 , 60 ℃ and 20 min of enrichment temperature and time. The developed method exhibited a good linearity in the range of 0.5–100.0 μg/mL with the coefficients of correction more than 0.9992, low limit of detection of 8.0–11.2 ng/mL, acceptable reproducibility below 4.45%, and satisfactory recovery in the range of 80.4–93.7% The results demonstrated that the proposed method was successfully applied to the extraction of alkaloids from lotus leaf. • An ionic liquid assisted mechanochemical extraction was developed. • This method was reinforced by in-situ cloud point extraction. • This method was suitable for simultaneous extraction and enrichment of alkaloids. • Environmental protection, efficient extraction and good repeatability were achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • An in-situ formation of ion pair assisted LLME method was developed. • This method was suitable for the separation of highly ionized basic compounds. • The proposed method was optimized by single-factor and multi-factor experiments. • Higher extraction efficiency, better reproducibility and environmental protection were achieved. A simple and rapid method for the determination of microsacle natural alkaloids, being based on the reaction of in-situ formation of ion pair assisted liquid–liquid microextraction (LLME) was established. Microsacle alkaloids and acid dyes formed ion pairs online, which were easily extracted by bonding reagent at an appropriate pH, so as to realize the enrichment and determination of alkaloids. The experimental parameters such as pH value, vortex time, dye types, amount of dye and solvent types were investigated and optimized. Under the optimum conditions, good linear relationships (R2 ≥ 0.9995) were obtained, the detection limits of the proposed method were between 8.9 and 16.7 ng/mL, and the average recoveries of four alkaloids ranged from 87.20 to 102.50%. These results demonstrated that the LLME procedure was a potential method for the separation and determination of alkaloids from natural medicinal materials. [ABSTRACT FROM AUTHOR]