Determination and quantification of active phenolic compounds in pigeon pea leaves and its medicinal product using liquid chromatography–tandem mass spectrometry

A novel method using liquid chromatography coupled to electrospray ionization mass spectrometry (LC-ESI-MS) has been optimized and established for the qualitative and quantitative analysis of ten active phenolic compounds originating from the pigeon pea leaves and a medicinal product thereof (Tongluo Shenggu capsules). In the present study, the chromatographic separation was achieved by means of a HiQ Sil C18V reversed-phase column with a mobile phase consisting of methanol and 0.1% formic acid aqueous solution. Low-energy collision-induced dissociation tandem mass spectrometry (CID-MS/MS) using the selected reaction monitoring (SRM) analysis was employed for the detection of ten analytes which included six flavonoids, two isoflavonoids and two stilbenes. All calibration curves showed excellent coefficients of determination (r(2) ≥ 0.9937) within the range of tested concentrations. The intra- and inter-day variations were below 5.36% in terms of relative standard deviation (RSD). The recoveries were 95.08-104.98% with RSDs of 2.06-4.26% for spiked samples of pigeon pea leaves. The method developed was a rapid, efficient and accurate LC-MS/MS method for the detection of phenolic compounds, which can be applied for quality control of pigeon pea leaves and related medicinal products.     

Ionic liquid‐based microwave‐assisted extraction for the determination of flavonoid glycosides in pigeon pea leaves by high‐performance liquid chromatography‐diode array detector with pentafluorophenyl column

In this study, an ionic liquid‐based microwave‐assisted extraction (ILMAE) followed by high‐performance liquid chromatograph y ‐diode array detector with a pentafluorophenyl column for the extraction and quantification of eight flavonoid glycosides in pigeon pea leaves is described. Compared with conventional extraction methods, ILMAE is a more effective and environment friendly method for the extraction of nature compounds from herbal plants. Nine different types of ionic liquids with different cations and anions were investigated. The results suggested that varying the anion and cation had significant effects on the extraction of flavonoid glycosides, and 1.0 M 1‐butyl‐3‐methylimidazolium bromide ([C4MIM]Br) solution was selected as solvent. In addition, the extraction procedures were also optimized using a series of single‐factor experiments. The optimum parameters were obtained as follows: extraction temperature 60°C, liquid–solid ratio 20:1 mL/g and extraction time 13 min. Moreover, an HPLC method using pentafluorophenyl column was established and validated. Good linearity was observed with the regression coefficients (r²) more than 0.999. The limit of detection (LODs) (S/N = 3) and limit of quantification (LOQs) (S/N = 10) for the components were less than 0.41 and 1.47 μg/mL, respectively. The inter‐ and intraday precisions that were used to evaluate the reproducibility and relative standard deviation (RSD) values were less than 4.57%. The recoveries were between 97.26 and 102.69%. The method was successfully used for the analysis of samples of pigeon pea leaves. In conclusion, the developed ILMAE‐HPLC‐diode array detector using pentafluorophenyl column method can be applied for quality control of pigeon pea leaves and related medicinal products.     

Quantitative determination of chlorogenic acid in Honeysuckle using microwave-assisted extraction followed by nano-LC-ESI mass spectrometry

The chlorogenic acid (CA) in Honeysuckle is determined and identified by nano-liquid chromatography-electrospray ionization mass spectrometry (nano-LC-ESI/MS) after extraction with microwave-assisted extraction (MAE). As a new sample preparation method for Honeysuckle, the MAE procedure is optimized, validated and compared with conventional methods including reflux extraction (RE) and ultrasonic extraction (USE). It is found that MAE gives the best result due to the highest extraction efficiency within shortest extraction time (only 4 min). Here, CA is determined by nano-LC-ESI/MS based on the calibration curve of its authentic standard. The method linearity, detection limit, precision and recovery are studied. The results show that the combined MAE and nano-LC-ESI/MS method has a linearity (R² 0.991, 0.8-20 ng mL⁻¹), a low limit of detection (0.5 ng mL⁻¹), good precision (R.S.D. = 2.54%) and a recovery (84.8%). The experiment has demonstrated that the nano-LC-ESI/MS following MAE is a fast and reliable method for quantitative analysis of CA in Honeysuckle.     

Negative-Pressure Cavitation Extraction of Four Main Vinca Alkaloids from <em>Catharanthus </em><em>r</em><em>oseus</em> Leaves

In the present study, an improved method termed negative-pressure cavitation extraction (NPCE) followed by reverse phase high-performance liquid chromatography (RP-HPLC) was developed for the extraction and quantification of vindoline (VDL), catharanthine (CTR), vincristine (VCR) and vinblastine (VLB) from Catharanthus roseus leaves. The optimized method employed 60-mesh particles, 80% ethanol, a negative pressure of -0.075 MPa, a solid to liquid ratio of 1:20, 30 min of extraction and three extraction cycles. Under these optimized conditions, the extraction yields of VDL, CTR, VCR and VLB are 0.5783, 0.2843, 0.018 and 0.126 mg/g DW, respectively. These extraction yields are equivalent to those from the well-known ultrasonic extraction method and higher than the yields from maceration extraction and heating reflux extraction. Our results suggest that NPCE-RP-HPLC represents an excellent alternative for the extraction and quantification of vinca alkaloids for pilot- and industrial-scale applications.     

Fast determination of chlorogenic acid in tobacco residues using microwave-assisted extraction and capillary zone electrophoresis technique

In this work, for the first time, capillary zone electrophoresis (CZE) technique combined with microwave-assisted extraction (MAE) was developed for the fast quantification of chlorogenic acid (CA) in tobacco residues. CA in tobacco residue samples were extracted by MAE technique, and then analyzed by CZE. As a new sample preparation method for tobacco residues, the MAE procedure is optimized, validated and compared with conventional methods including ultrasonic extraction (USE) and reflux extraction (RE). It is found that MAE gives the best result due to the highest extraction efficiency within shortest extraction time (only 4.0 min). Here, CA is determined by CZE based on the calibration curve of its authentic standard. The method linearity, detection limit, precision and recovery are studied. The results show that the combined MAE and CZE method has a linearity (R² 0.991, 0.003-0.5 mg ml⁻¹), a limit of detection (0.003 mg ml⁻¹), a limit of quantification (0.01 mg ml⁻¹), good precision (R.S.D. = 4.28%) and a finer recovery (89.0%). The proposed method was successfully applied to the analysis of CA in tobacco residue samples. The experiment results have demonstrated that the CZE combined with MAE is a convenient, fast, economical and reliable method for the determination of CA in tobacco residues.     

Rapid method for the determination of 16 organochlorine pesticides in sesame seeds by microwave-assisted extraction and analysis of extracts by gas chromatography-mass spectrometry

A method for the multiresidue analysis of 16 organochlorine insecticides in sesame seeds has been developed. The method is based on the microwave-assisted extraction (MAE) of the sesame seeds by the use of a water-acetonitrile mixture followed by Florisil clean-up of the extracts and subsequent analysis by gas chromatography-mass spectrometry (GC/MS) in the selected ion monitoring (SIM) mode. MAE operational parameters (extraction solvent, temperature and time, extractant volume) were optimized with respect to extraction efficiency of the target compounds from sesame seeds with 46% oil content. Recoveries >80% with relative standard deviations (RSD) <12% were obtained for all compounds under the selected parameters. The Florisil clean-up step proved sufficient for the removal of co-extracted substances so that no adverse effect on the chromatographic system was observed. Limit of quantification (LOQ) values were in the range of 5-10 microg/kg. The proposed method was applied in the analysis of sesame seed samples imported to Greece.     

Determination of lignans in flaxseed using liquid chromatography with time-of-flight mass spectrometry

A new method of flaxseed-derived lignan determination was developed using HPLC with high-resolution time-of-flight MS (TOF-MS), optimized, and compared to two existing methods (HPLC/MS/MS and GC/MS). The limits of detection (LODs) for HPLC/TOF-MS (0.002–0.043 pg) were comparable with those of the optimized and improved HPLC/MS/MS (0.001–0.015 pg), whereas the LODs for the optimized GC/MS were higher (0.02–3.0 pg, yet lower than reported before). Using the newly developed detection and separation methods, several key flaxseed sample preparation parameters (including extraction, hydrolysis, and sample purification) were evaluated resulting in the development of efficient protocol for lignan quantification from flaxseed hulls and embryos. The results confirmed the importance of quantification of both aglycones and unhydrolyzed glucosides in order to obtain the total lignan estimates.     

Rapid extraction of water soluble organic compounds from airborne particulate matter.

Water soluble organic compounds (WSOC) in airborne particulate matter (PM) have received considerable attention in recent years due to their abundance and their importance in atmospheric processes. The analysis of WSOC is necessary for quantifying the relative contribution of individual organic compounds to the total WSOC mass. In the present work, we evaluated the performance of a microwave-assisted extraction (MAE) method for the determination of WSOC in PM and compared the data with those of a conventional ultrasonic extraction (USE). The experimental results showed that the MAE method requires a shorter extraction time (5 min) compared to USE. The isolated water-soluble organic fraction of PM was subsequently analyzed using ion chromatography (IC) for low molecular weight organic acids. The rapid MAE method was used in conjunction with IC for the analysis of organic acids in PM samples, collected from different sources.     

Green Extraction of Antioxidant Flavonoids from Pigeon Pea (Cajanus cajan (L.) Millsp.) Seeds and Its Antioxidant Potentials Using Ultrasound-Assisted Methodology

Pigeon pea is an important pea species in the Fabaceae family that has long been used for food, cosmetic, and other phytopharmaceutical applications. Its seed is reported as a rich source of antioxidants and anti-inflammatory flavonoids, especially isoflavones, i.e., cajanin, cajanol, daidzein, and genistein. In today’s era of green chemistry and green cosmetic development, the development and optimization of extraction techniques is increasing employed by the industrial sectors to provide environmentally friendly products for their customers. Surprisingly, there is no research report on improving the extraction of these isoflavonoids from pigeon pea seeds. In this present study, ultrasound-assisted extraction (USAE) methodology, which is a green extraction that provides a shorter extraction time and consumes less solvent, was optimized and compared with the conventional methods. The multivariate strategy, the Behnken–Box design (BBD) combined with response surface methodology, was employed to determine the best extraction conditions for this USAE utilizing ethanol as green solvent. Not only in vitro but also cellular antioxidant activities were evaluated using different assays and approaches. The results indicated that USAE provided a substantial gain of ca 70% in the (iso)flavonoids extracted and the biological antioxidant activities were preserved, compared to the conventional method. The best extraction conditions were 39.19 min with a frequency of 29.96 kHz and 63.81% (v/v) aqueous ethanol. Both the antioxidant and anti-aging potentials of the extract were obtained under optimal USAE at a cellular level using yeast as a model, resulting in lower levels of malondialdehyde. These results demonstrated that the extract can act as an effective activator of the cell longevity protein (SIR2/SIRT1) and cell membrane protector against oxidative stress. This finding supports the potential of pigeon pea seeds and USAE methodology to gain potential antioxidant and anti-aging (iso)flavonoids-rich sources for the cosmetic and phytopharmaceutical sectors.     

Determination of Carbon‐based Engineered Nanoparticles in Marketed Fish by Microwave‐assisted Extraction and Liquid Chromatography‐atmospheric Pressure Photoionization‐tandem Mass Spectrometry

An optimized method for the determination of two major carbon‐based engineered nanoparticles (C₆₀ and C₇₀) in marketed fish samples is described. The method involves the use of microwave‐assisted extraction (MAE) coupled with liquid chromatography ‐ tandem mass spectrometry with atmospheric pressure photoionization (LC‐APPI‐MS/MS). Factors affecting the extraction efficiency of the analytes from fish samples were optimized by a central composite design method. The optimal extraction temperature and time for MAE were found to be 233 °C for 22 min, and the extraction solution was composed of toluene and acetone in a ratio of 4.64:1. The limits of quantitation (LOQs) were 0.1 and 0.05 ng/g for C₆₀ and C₇₀, respectively. The precision for these analytes at two spiked levels, as indicated by relative standard deviations (RSDs), were less than 10% for both intra‐ and inter‐day analysis. Accuracy, expressed as the mean extraction recovery, was between 85 and 98%. The method was further validated based on EU Commission Decision 2002/657/EC, including a decision limit (CCα) and detection capability (CCβ) for marketed fish samples.     

Determination of vitexin and isovitexin in pigeonpea using ultrasonic extraction followed by LC-MS

A method based on ultrasonic extraction (USE) followed by LC-MS is presented for the determination of vitexin and isovitexin in pigeonpea extracts in this study. The influential parameters of the USE procedure were optimized, and the optimal conditions were as follows: extraction solvent, 60% ethanol solution; liquid/solid ratio 10:1 (mL/g), extraction power, 250 W; temperature, 40-50 degrees C; and three extraction cycles, each cycle 15 min. Validation of the USE method was performed in terms of repeatability and reproducibility. RSDs for extraction yields were lower than 5.85 and 8.09%, respectively. The LOD and LOQ of chromatographic determination were 0.96 and 3.2 ng/mL for vitexin and 0.84 and 2.8 ng/mL for isovitexin. The method was also successfully applied for the determination of vitexin and isovitexin in stems, leaves, and root extracts of pigeonpea. From all these results, we may conclude that the developed method is appropriate for the quality control of pigeonpea and other plant extract products developed from pigeonpea.     

Study of polyethylene glycol as a green solvent in the microwave-assisted extraction of flavone and coumarin compounds from medicinal plants

In this paper, the application of polyethylene glycol (PEG) aqueous solution as a green solvent in microwave-assisted extraction (MAE) was firstly developed for the extraction of flavone and coumarin compounds from medicinal plants. The PEG solutions were optimized by a mono-factor test, and the other conditions of MAE including the size of sample, liquid/solid ratio, extraction temperature and extraction time were optimized by means of an orthogonal design L(9) (3(4)). Subsequently, PEG-MAE, organic solvent-MAE, and conventional heating reflux extraction (HRE) were evaluated with nevadensin extraction from Lysionotus pauciflorus, aesculin and aesculetin extraction from Cortex fraxini. Furthermore, the mechanism of PEG-MAE was investigated, including microwave-absorptive property and viscosity of PEG solutions, the kinetic mechanism of PEG-MAE and different microstructures of those samples before and after extraction. Under optimized conditions, the extraction yields of nevadensin from L. pauciflorus, aesculin and aesculetin from C. fraxini were 98.7%, 97.7% and 95.9% in a one-step extraction, respectively. The recoveries of nevadensin, aesculin and aesculetin were in the range of 92.0-103% with relative standard derivation lower than 3.6% by the proposed procedure. Compared with organic solvent-MAE and conventional extraction procedures, the proposed methods were effective and alternative for the extraction of flavone and coumarin compounds from medicinal plants. On the basis of the results, PEG solution as a green solvent in the MAE of active compounds from medicinal plants showed a great promising prospect.     

Hyphenation of optimized microfluidic sample preparation with nano liquid chromatography for faster and greener alkaloid analysis

A glass liquid–liquid extraction (LLE) microchip with three parallel 3.5 cm long and 100 μm wide interconnecting channels was optimized in terms of more environmentally friendly (greener) solvents and extraction efficiency. In addition, the optimized chip was successfully hyphenated with nano-liquid chromatography with ultraviolet and mass spectrometric detection (nanoLC–UV–MS) for on-line analysis. In this system, sample pretreatment, separation and detection are integrated, which significantly shortens the analysis time, saves labor and drastically reduces solvent consumption. Strychnine was used as model analyte to determine the extraction efficiency of the optimized 3-phase chip. Influence of organic solvent, pH of feed phase, type of alkaloid, and flow rates were investigated. The results demonstrated that the 3-phase chip nanoLC–UV/MS hyphenation combines rapid (∼25 s) and efficient (extraction efficiency >90%) sample prep, with automated alkaloid analyses. The method was applied to real samples including Strychnos nux-vomica seeds, Cephaelis ipecacuanha roots, Atropa belladonna leaves, and Vinca minor leaves.     

An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.     

Fast miniaturised sample preparation for the screening and comprehensive two-dimensional gas chromatographic determination of polychlorinated biphenyls in sludge

Polychlorinated biphenyls (PCBs) in sludge are usually extracted by a technique such as Soxhlet with subsequent fractionation prior to long GC runs using GC-ECD or GC-HRMS. In this study, the extraction of selected chlorinated biphenyls (CBs) from a spiked sludge sample by three rapid techniques, i.e. ultrasonic (USE), pressurised-liquid (PLE), and microwave-assisted (MAE) extraction using a domestic microwave, was studied, with subsequent direct GC-ECD, GC-MS, or GC x GC-microECD analysis of the extracts. The main goal was to select an appropriate, and miniaturised, extraction method after only a brief optimisation and demonstrate the power of GC x GC analysis of dirty extracts. For PLE similar CB recoveries were found when extracting with either n-hexane or n-hexane/acetone (1/1). For USE and MAE, n-hexane/acetone (1/1) was the preferred extraction solvent. USE gave the best recoveries (80-95%; except 130% for CB 105). The only clean-up needed prior to GC-MS or GC x GC-gECD analysis was the removal of sulphur-containing compounds. GC-ECD was not suitable for these dirty extracts. The lowest LODs for the CBs (20 fg or 0.1 ng/g sludge) were found when combining USE and GC x GC-microECD, because of the powerful extraction, high separation power and excellent detectability provided by this technique.     

An efficient and fast microwave-assisted extraction method developed for the simultaneous determination of 18 organochlorine pesticides in sediment

An efficient and fast microwave-assisted extraction (MAE) method followed by gas chromatographic separation with mass spectrometric detection (GC–MS) was developed for the extraction of 18 organochlorine pesticides (OCPs) from sediment. Parameters affecting the MAE procedure such as the type and volume of the extraction solvent, irradiation power, temperature and irradiation time were successfully optimised. Under the optimal conditions, extraction efficiencies in the range of 73.4–119% were obtained with THF–HEX (9:1, v/v) for all OCPs studied. The method was linear over the range of 2.9–5000 ng g^?1 with determination coefficients (r²) higher than 0.992 for all analytes. The limits of detection, LODs (S/N = 3), obtained varied from 1.0 to 2.2 ng g^?1 and limits of quantification, LOQs (S/N = 10) were between 2.9 and 6.8 ng g^?1. The proposed method was successfully applied to the analysis of real sediment samples and acceptable recoveries from 70.1 to 124% with RSDs ≤14.8% were obtained. 10 OCPs were determined below their LOQ and 8 OCPs in the range of 124–2830 ng g^?1. The MAE method was compared with Soxhlet, shake flask and ultrasonic solvent extraction techniques. Thus, the MAE–GC–MS method could efficiently be used for selective extraction and quantification of the target analytes from the complex sediment matrices.     

Targeted analysis of multiple pharmaceuticals,plant toxins and other secondary metabolites in herbal dietary supplements by ultra-high performance liquid chromatography–quadrupole-orbital ion trap mass spectrometry

In this study, an ultra-high performance liquid chromatography–quadrupole-orbital ion trap mass spectrometry (UHPLC–Q-orbitrap MS) method was developed and validated for simultaneous determination of 96 pharmaceuticals, plant toxins, and other plant secondary metabolites in herbal dietary supplements. Target analytes were extracted from samples using the QuEChERS (quick easy cheap effective rugged safe) procedure. The instrument was operated in full MS–data dependent tandem mass spectrometry (full MS–dd-MS/MS) acquisition mode which enabled collection of quantitative high resolution (HR) full mass spectral data and confirmatory HR MS/MS data in a single run. The method provided excellent selectivity in both full MS and dd-MS/MS mode. Under optimized collision energy settings, product ion spectra containing both precursor and two or more product ions were obtained for most of the analytes. Limits of detection (LODs) and limits of quantification (LOQs) for the method differed significantly for the examined matrices. LODs ≤ 10 μg kg⁻¹ and LOQs ≤ 50 μg kg⁻¹ were obtained for 48 to 81% of target compounds across five different matrices. With the exception of highly polar analytes, the optimized QuEChERS extraction procedure provided acceptable recoveries in the range 70%–120%. The precision of the method, characterized as the relative standard deviation (RSD, n = 5), was ≤25% and ≤18% at spiking concentrations of 50 μg kg⁻¹ and 500 μg kg⁻¹, respectively. Because of variations in matrix effects in extracts of herbal dietary supplements that differed in composition, the method of standard additions and an approach based on dilution of matrix components followed by quantification using solvent standards were applied for quantification. The procedure was used to examine commercial dietary supplements for the 96 analytes of interest. To the best of our knowledge, this is the first report of an integrated analysis and quantification of this wide range of compounds.     

Liquid chromatography-tandem mass spectrometry determination for multiclass pesticides from insect samples by microwave-assisted solvent extraction followed by a salt-out effect and micro-dispersion purification

The effects of phyto-pharmaceutic compounds (PPCs), such as neonicotinoids, on wildlife reproduction and survival are a rising concern. Yet, understanding the biological consequences of PPC use is particularly complex given the large diversity of PPCs and their derivatives to which wildlife can be exposed. Here, we present a simple and sensitive method for the simultaneous detection and quantification of multiclass PPCs (54 molecules) in single insect boluses (<0.05 g dry mass) by ultra-high pressure liquid chromatography coupled to a tandem mass spectrometer (LC-MS/MS). A key part of this new method is the use of a two-step extraction method combining (i) the high efficiency of a microwave-assisted solvent extraction (MAE) for extracting analytes that might be tightly bound to environmental matrices and (ii) the versatility of a salt-out effect adapted from the QuEChERS methodology allowing the extraction and purification of a wide array of analytes. This microwave-assisted salt-out extraction (MASOE) approach was compared to classical extraction methods including matrix solid phase dispersion (MSPD), microwave-assisted extraction (MAE), and the QuEChERS method. Average recoveries for 54 analytes ranged from 49% to 106%, (relative standard deviations <22%). The limits of detection (LODs) and quantification (LOQs) were in the ranges of 0.10–3.00 ng g⁻¹ and 0.40–7.00 ng g⁻¹, respectively. We applied this method to analyse 881 insect boluses collected from Tree Swallow (Tachycineta bicolour) nestlings along an agricultural intensification gradient in southern Québec (Canada). We detected 25 PPCs out of the 54 considered. We detected at least one PPC in 30% of samples and were able to quantify at least one of them in 17% of samples. Our study shows that the MASOE method should prove to be a powerful tool for studying the fate and impacts of PPCs on wildlife.     

Ionic Liquid-Based Ultrasonic/Microwave-Assisted Extraction Combined with UPLC for the Determination of Anthraquinones in Rhubarb

Ionic liquid-based ultrasonic/microwave-assisted extraction (IL-UMAE) of five anthraquinones (physcion, chrysophanol, emodin, rhein, and aloe-emodin) from rhubarb was first studied. Several parameters of UMAE were optimized, and the results were compared with of the heat-reflux extraction (HRE), ultrasound, and microwave-assisted extraction (MAE and UAE). The optimal UMAE conditions were as follows: the solvent was 2.0 mol L^?1 1-butyl-3-methylimidazolium bromide [bmim]Br solution, the ration of solid/liquid (g mL^?1) was 1:15, time was 2 min, and microwave power was 500 W. Under these UMAE conditions, total content of five anthraquinones was 28.00 mg g^?1. Compared with the conventional HRE, regular MAE and UAE techniques, the proposed approach exhibited higher efficiency (18.90?C24.40% enhanced) and shorter extraction time (from 6 h to 2 min). The anthraquinones were then determined by ultra performance liquid chromatography (UPLC). Based on optimized conditions, contents of physcion, chrysophanol, emodin, rhein and aloe-emodin in rhubarb collected from different cultivated areas were 0.68?C2.99, 5.03?C15.40, 0.48?C4.34, 0.025?C3.93 and 0.26?C2.56 mg g^?1, respectively. This study suggests that IL-UMAE was an efficient, rapid, simple and green preparation technique.     

Determination of main taxoids in Taxus species by microwave‐assisted extraction combined with LC‐MS/MS analysis

A method based on microwave‐assisted extraction (MAE) has been developed for the determination of paclitaxel and five related taxoids, namely 10‐deacetylbaccatin III (10‐DAB III), cephalomannine, 10‐deacetylpaclitaxel (10‐DAT), 7‐xyl‐10‐ deacetylpaclitaxel (7‐xyl‐10‐DAT), and 7‐epi‐10‐deacetylpaclitaxel (7‐epi‐10‐DAT) in Taxus species in this study. The influential parameters of the MAE procedure were optimized, and the optimal conditions were as follows: extraction solvent 80% ethanol solution, solid/liquid ratio 1:10 (g/mL), temperature 50°C, and three extraction cycles, each cycle 10 min. The method validation for LC‐MS/MS analysis was performed. The LOD and LOQ were 3.16–9.20 and 12.20–30.45 ng/mL, respectively. Repeatability and reproducibility for the six taxiods with RSD ranged from 2.78 to 3.85% and from 5.26 to 6.60%. The recoveries of the method for the six taxoids were 92.6–105.6%. The developed MAE‐LC‐MS/MS method was also successfully applied to determine the contents of six taxoids in different Taxus species.