Ion pair assisted micro matrix solid phase dispersion extraction of alkaloids from medical plant

A novel micro matrix solid phase dispersion method was successfully used for the extraction of quaternary alkaloids in Phellodendri chinensis cortex. The elution of target compounds was accomplished with sodium hexanesulfonate as the eluent solvent. A neutral ion pair was formed between ion-pairing reagent and positively charged alkaloids in this process, which was beneficial for selectively extraction of polar alkaloids. Several parameters were optimized and the optimal conditions were listed as follows: silica gel as the sorbent, silica to sample mass ratio of 1:1, the grinding time of 1 min. The exhaustive elution of targets was achieved by 200 µL methanol/water (9:1) containing 150 mM sodium hexane sulfonate at pH 4.5. The method validation covered linearity, recovery, precision of intraday and interday, limits of detection, limits of quantitation, and repeatability. This established method was rapid, simple, environmentally friendly, and highly sensitive.     

Miniaturized matrix solid‐phase dispersion coupled with supramolecular solvent‐based microextraction for the determination of paraben preservatives in cream samples

An analytical method is presented for the determination of paraben preservatives in semisolid cream samples by matrix solid‐phase dispersion combined with supramolecular solvent‐based microextraction. Due to the oily and sticky nature of the sample matrix, parabens were first extracted from the samples by matrix solid‐phase dispersion using silica as sorbent material with a clean‐up performed with tetrahydrofuran in the elution step. The eluate (500 μL), 1‐decanol (120 μL), and water (4.4 mL) were then mixed in a polyethylene pipette to form supramolecular solvent. Finally, the analytes in the supramolecular solvent were separated and determined by liquid chromatography with ultraviolet detection. Under optimal extraction conditions, the extraction recoveries of the studied compounds were obtained in the range of 63–83%. The limits of detection for the analytes were between 0.03 and 0.04 μg/g. The precision of the method varied between 4.0–6.7 (intraday) and 6.2–7.9% (interday). Finally, the optimized procedure was applied to the determination of the target preservatives in a variety of cream samples (diaper rash, skin allergy, face and hand moisturizing) with satisfactory recoveries (86–102%).     

Solid acids assisted matrix solid‐phase dispersion microextraction of alkaloids by capillary electrophoresis coupled with quadrupole time‐of‐flight mass spectrometry

The quantification of three alkaloids is important because quantitative study is a means of assessing the reliability of the experimental method, and three alkaloids of peimine, peiminine, and peimisine are main active ingredients in Chinese Pharmacopoeia 2015. An effective method based on the matrix solid‐phase dispersion microextraction was developed for the extraction of alkaloid compounds in Fritillariae Thunbergii Bulbus. Target analytes were analyzed by capillary electrophoresis coupled with quadrupole time‐of‐flight mass spectrometry. The optimized experimental condition was that 50 mg Fritillariae Thunbergii Bulbus was blended homogeneously with 10 mg citric acid for 5 min. Two hundred microliters of water acidized by 1 mol/L hydrochloric acid (pH = 4.5) was selected to elute tested alkaloids. The results demonstrated that the investigated method had low limits of detection (1.32–1.59 ng/mL), good recoveries (86.63–98.12%), and reproducibility (relative standard deviations of peak areas < 0.87%). The proposed matrix solid‐phase dispersion microextraction coupled with capillary electrophoresis combined with quadrupole time‐of‐flight mass spectrometry was successfully applied for the extraction of alkaloids in plants.     

Simultaneous determination of organophosphorus pesticides in Chinese herbal medicines by microwave‐assisted extraction coupled with dispersive‐solid phase extraction and gas chromatography

A reliable, rapid and nontoxic analytical method was proposed for the simultaneous determination of 16 organophosphorus pesticides in Chinese herbal medicines. The pesticides were extracted by ethanol and the experimental variables, such as temperature, extraction time and volume of ethanol, were optimized through orthogonal array experimental design. Cleanup of extracts was performed with dispersive‐solid phase extraction using primary secondary amine as the sorbent. The determination of pesticides in the final extracts was carried out by gas chromatography–flame photometric detection. Under optimized conditions the obtained recoveries, except for isocarbophos, were in the range 73.8–123%, with relative standard deviations equal to or lower than 15.2% and limits of detection ranging from 0.001 to 0.009 mg/kg. Copyright © 2010 John Wiley & Sons, Ltd.     

Simultaneous determination of seven compounds in Chinese patent medicines Chenxiangqu by matrix solid‐phase dispersion coupled with ultra high performance liquid chromatography and quadrupole time‐of‐flight mass spectrometry

A simple, efficient, and sensitive strategy by coupling matrix solid‐phase dispersion with ultra high performance liquid chromatography quadrupole time‐of‐flight mass spectrometry was proposed to extract and determine three types of components (including seven analytes) in Chinese patent medicines Chenxiangqu. The highly ordered mesoporous material Fe‐SBA‐15 synthesized under weakly acidic conditions was selected as a dispersant in matrix solid phase dispersion extraction for the first time. Several parameters including the mass ratio of sample to dispersant, the type of dispersant, the grinding time, and the elution condition were investigated in this work. Under the optimized conditions, 20 compounds were identified by quadrupole time‐of‐flight mass spectrometry and seven analytes were quantified. The results demonstrated that the developed method has good linearity (r > 0.9995), and the limits of detection of the analytes were as low as 0.55 ng/mL. The recoveries of all seven analytes ranged from 97.6 to 104.6% (relative standard deviation < 3.4%). Finally, the improved method was successfully applied to determination of five batches of Chenxiangqu samples, which provided a robust method in quality control of Chinese patent medicines Chenxiangqu. The developed strategy also shows its great potential in analysis of complex matrix samples.     

Matrix solid‐phase dispersion coupled with hollow fiber liquid phase microextraction for determination of triazine herbicides in peanuts

Two extraction procedures, matrix solid‐phase dispersion and hollow fiber liquid‐phase microextraction, were combined and applied to determine triazine herbicides in peanut samples. The results showed that the established method has high extraction efficiency and could greatly eliminate the interferences from complex matrix samples. A series of important experimental parameters were all investigated in detail. Under the optimal conditions, the developed method has the limits of detection for triazine herbicides in the range of 0.05 to 1.71 μg/kg. Moreover, it has the recovery in the range of 80.4–120.0% with relative standard deviations of equal or lower than 8.9%. The established method may have a great potential in separation, enrichment, and purification of triazines from complex fatty solid samples.     

莪术中挥发性成分的微波辅助固相顶空气相色谱法分析

将微波无溶剂提取(SFME)与顶空气相色谱(HS-GC)在线联用,建立了中药材的微波辅助固相顶空气相色谱法(MASP-HSGC),并用该方法快速直接分析了莪术药材中的挥发性成分。研究中对色谱条件、微波作用时间、微波作用功率等因素进行了考察,并以莪术醇为标准品考察了回收率和检出限,同时测定了莪术醇在莪术药材中的含量。对采用水蒸气蒸馏法(HD)和SFME法获得的莪术挥发油进行了气相色谱-质谱（GC-MS）分析,所得结果与所建立方法的结果进行对比。结果表明: HD-GC、SFME-GC和MASP-HSGC法所测得的化合物分别为35、33和40种;3种方法测得的莪术醇含量分别为（0.294±0.015）、（0.331±0.023）和（0.297±0.009） mg/g。该法简便快速,可用于莪术中挥发性成分的分离分析。     

基质固相分散-反相液相色谱法测定蔬菜中二甲戊乐灵农药残留

应用基质固相分散-反相液相色谱技术建立了提取、检测蔬菜中二甲戊乐灵农药残留的分析方法。研究了提取及测定条件对检测二甲戊乐灵的影响,确定了最佳提取条件:萃取吸附剂为弗罗里硅土,样品与弗罗里硅土吸附剂的比例为1∶4,洗脱剂为20 mL乙酸乙酯。二甲戊乐灵的测定线性范围为0.02~2.0 mg/L、r0.999。应用此方法测定了某些蔬菜样品中二甲戊乐灵农药残留,测定相对标准偏差为2.2%~5.2%。在几种蔬菜中的加标回收率为85%~93%,当样品为0.5 g时,方法检出限在5.5~10 ng范围内。     

Solid phase microextraction and gas chromatography mass spectrometry analysis of Zingiber officinale and Curcuma longa

SPME analysis of Zingiber officinale Roscoe and Curcuma longa L. were performed by using a DVB/CARB/PDMS fiber. The SPME analysis of Zingiber officinale showed that the main components found were camphene (7.27%), geranial (8.37%), α-zingiberene (14.50%), α-farnesene (9.14%), β-bisabolene (6.52%), and β-sesquiphellandrene (9.92%). The SPME analysis of Curcuma longa showed that main components were p-cymene (12.96%) and ar-turmerone (12.08%). Other components were β-phellandrene (7.86%), terpinolene (6.97%), ar-curcumene (8.53%), α-zingiberene (8.46%), and β-sesquiphellandrene (7.37%).     

Simultaneous determination and qualitative analysis of six types of components in Naoxintong capsule by miniaturized matrix solid‐phase dispersion extraction coupled with ultra high‐performance liquid chromatography with photodiode array detection and quadrupole time‐of‐flight mass spectrometry

A simple and effective sample preparation process based on miniaturized matrix solid‐phase dispersion was developed for simultaneous determination of phenolic acids (gallic acid, chlorogenic acid, ferulic acid, 3,5‐dicaffeoylqunic acid, 1,5‐dicaffeoylqunic acid, rosmarinic acid, lithospermic acid, and salvianolic acid B), flavonoids (kaempferol‐3‐O‐rutinoside, calycosin, and formononetin), lactones (ligustilide and butyllidephthalide), monoterpenoids (paeoniflorin), phenanthraquinones (cryptotanshinone), and furans (5‐hydroxymethylfurfural) in Naoxintong capsule by ultra high‐performance liquid chromatography. The optimized condition was that 25 mg Naoxintong powder was blended homogeneously with 100 mg Florisil PR for 4 min. One milliliter of methanol/water (75:25, v/v) acidified by 0.05% formic acid was selected to elute all components. It was found that the recoveries of the six types of components ranged from 61.36 to 96.94%. The proposed miniaturized matrix solid‐phase dispersion coupled with ultra high‐performance liquid chromatography was successfully applied to simultaneous determination of the six types of components in Naoxintong capsules. The results demonstrated that the proposed miniaturized matrix solid‐phase dispersion coupled with ultra high‐performance liquid chromatography could be used as an environmentally friendly tool for the extraction and determination of multiple bioactive components in natural products.     

Analysis of pesticide residues in fruit and vegetables by matrix solid phase dispersion (MSPD) and different gas chromatography element-selective detectors

Summary A comparison between different element selective detectors for the determination of organophosphorus and organochlorine pesticide residues, from fruit and vegetables, was performed by capillary GC with electron capture detector (ECD), nitrogen phosphorus detector (NPD), flame photometric detector (FPD) in the sulphur and phosphorus modes, and mass spectrometry detector (MSD) in selected ion monitoring (SIM) mode. Pesticides were extracted from the different foodstuffs by Matrix Solid Phase Dispersion (MSPD). Recoveries of 41–108 % with relative standard deviation of 2–14 % in the concentration range 0.5–10 μg L⁻¹ were obtained in oranges, lemons, grapefruit, pears, plums, lettuces and tomatoes. The results demonstrated that the extracts of all the samples can be analyzed by the detectors used since no interfering co-extracted compounds were detected.     

Determination of neonicotinoid insecticides in environmental samples by micellar electrokinetic chromatography using solid‐phase treatments

A sensitive and reliable method based on MEKC has been developed and validated for trace determination of neonicotinoid insecticides (thiamethoxam, acetamiprid, and imidacloprid) and the metabolite 6‐chloronicotinic acid in water and soil matrices. Optimum separation of the neonicotinoid insecticides was obtained on a 58 cm long capillary (75 μm id) using as the running electrolyte 40 mM SDS, 5 mM borate (pH 10.4), and 5% (v/v) methanol at a temperature of 25°C, a voltage of 25 kV and with hydrodynamic injection (10 s). The analysis time was less than 7 min. Prior to MEKC determination, the samples were purified and enriched by carrying out extraction‐preconcentration steps. For aqueous samples, off‐line SPE with a sorptive material such as Strata‐X (polymeric hydrophobic sorbent) and octadecylsilane (C₁₈) was carried out to clean up and preconcentrate the insecticides. However, for soil samples, matrix solid‐phase dispersion (MSPD) was applied with C₁₈ used as the dispersant. Good linearity, accuracy, and precision were obtained and the detection limits were in the range between 0.01 and 0.07 μg mL^?1 for river water and 0.17 and 0.37 μg g^?1 for soil samples. Recovery levels reached greater than 92% for all of the assayed neonicotinoids in river water samples with Strata‐X. In soil matrices, the best recoveries (63–99%) were obtained with MSPD.     

Ionic liquid vortex‐simplified matrix solid‐phase dispersion for the simultaneous determination of terpenoids,crocins, quinic acid derivatives and flavonoids in Gardeniae fructus by UHPLC

A novel ionic‐liquid‐based vortex‐simplified matrix solid‐phase dispersion method using 2,6‐dimethyl‐β‐cyclodextrin was established by ultra high performance liquid chromatography coupled with a photodiode array detector. 2,6‐Dimethyl‐β‐cyclodextrin was first used as a promising adsorbent in this proposed method for simultaneous determination of eight compounds in Gardeniae fructus. These compounds are terpenoids (geniposidic acid, genipin‐1‐β‐D‐gentiobioside, geniposide, 8‐o‐acetyl shanzhiside methyl ester), crocins (crocin‐I, crocin‐II), quinic acid derivatives (chlorogenic acid), and flavonoids (isoquercitrin), respectively. Several parameters were investigated in the adsorption and desorption processes to obtain the optimal conditions, including 2,6‐dimethyl‐β‐cyclodextrin as sorbent, 0.5 mL 100 mM 1‐dodecyl‐3‐methylimidazolium hydrogen sulfate as the extraction solvent, 2:1 of sample/sorbent ratio, grinding for 2 min and vortexing for 60 s. The recoveries of the eight compounds ranged from 96.6 to 100% (<3.50%). The limits of detection and quantification were in the range of 0.02–0.30 and 0.06–1.25  μg/mL, respectively. Meanwhile, a good linearity was attained with r values (>0.9997). The established method showed higher extraction efficiency and less reagent consumption than traditional matrix solid phase dispersion and ultrasonic‐assisted extraction. Hence, it could be applied for sample preparation and analysis of natural products.     

Miniaturized matrix solid phase dispersion procedure and solid phase microextraction for the analysis of organochlorinated pesticides and polybrominated diphenylethers in biota samples by gas chromatography electron capture detection

This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD) using C18 as dispersant and acetonitrile–water as eluting solvent for the analysis of legislated organochlorinated pesticides (OCPs) and polybrominated diphenylethers (PBDEs) in biota samples by GC with electron capture (GC-ECD). The method has compared Florisil^®-acidic Silica and C18 as dispersant for samples as well as different solvents. Recovery studies showed that the combination of C18–Florisil^® was better when using low amount of samples (0.1 g) and with low volumes of acetonitrile–water (2.6 mL). The use of SPME for extracting the analytes from the solvent mixture before the injection resulted in detection limits between 0.3 and 7.0 μg kg⁻¹ (expressed as wet mass). The miniaturized procedure was easier, faster, less time consuming than the conventional procedure and reduces the amounts of sample, dispersant and solvent volume by approximately 10 times. The proposed procedure was applied to analyse several biota samples from different parts of the Comunidad Valenciana.     

Determination of fluoroquinolones in blood by matrix solid-phase dispersion extraction and CE

A simple and rapid method for the determination of residues of four fluoroquinolones in blood samples was developed. The method was based on matrix solid‐phase dispersion extraction followed by CE with ultraviolet detection. 1‐Butyl‐3‐methylimidazolium tetrafluoroborate aqueous solution was used as the background electrolyte for the separation of fluoroquinolones. The average recoveries of the four fluoroquinolones at two spiked levels ranged from 54.0 to 86.4% for pig blood, and 45.4 to 79.9% for deer blood, with the relative standard deviations <9.45%. Detection limits for the four fluoroquinolones in blood sample ranged from 0.15 to 0.31 μg/mL.     

Miniaturized matrix solid‐phase dispersion combined with ultrasound‐assisted dispersive liquid–liquid microextraction for the determination of three pyrethroids in soil

A simple and miniaturized pretreatment procedure combining matrix solid‐phase dispersion (MSPD) with ultrasound‐assisted dispersive liquid–liquid microextraction (UA‐DLLME) technique was proposed in first time for simultaneous determination of three pyrethroids (fenpropathrin, cyhalothrin and fenvalerate) in soils. The solid samples were directly extracted using MSPD procedure, and the eluent of MSPD was used as the dispersive solvent of the followed DLLME procedure for further purification and enrichment of the analytes before GC‐ECD analysis. Good linear relationships were obtained for all the analytes in a range of 5.0–500.0 ng/g with LOQs (S/N=10) ranged from 1.51 to 3.77 ng/g. Average recoveries at three spiked levels were in a range of 83.6–98.5% with RSD≤7.3%. The present method combined the advantages of MSPD and DLLME, and was successfully applied for the determination of three pyrethroids in soil samples.     

Application of multiwall carbon nanotubes-based matrix solid phase dispersion extraction for determination of hormones in butter by gas chromatography mass spectrometry

The multiwall carbon nanotubes (MWCNTs)-based matrix solid phase dispersion (MSPD) was applied for the extraction of hormones, including 17-α-ethinylestradiol, 17-α-estradiol, estriol, 17-β-estradiol, estrone, medroxyprogesterone, progesterone and norethisterone acetate in butter samples. The method includes MSPD extraction of the target analytes from butter samples, derivatization of hormones with heptafluorobutyric acid anhydride-acetonitrile mixture, and determination by gas chromatography-mass spectrometry. The mixture containing 0.30 g graphitized MWCNTs and 0.10 g MWCNTs was selected as absorbent. Ethyl acetate was used as elution solvent. The elution solvent volume and flow rate were 12 mL and 0.9 mL min(-1), respectively. The recoveries of hormones obtained by analyzing the five spiked butter samples were from 84.5 to 111.2% and relative standard deviations from 1.9 to 8.9%. Limits of detection and quantification for determining the analytes were in the range of 0.2-1.3 and 0.8-4.5 μg kg(-1), respectively. Compared with other traditional methods, the proposed method is simpler in the operation and shorter in the sample pretreatment time.     

A dual preconcentration method by combining micro matrix solid-phase dispersion extraction with field-enhanced sample injection and micelle to cyclodextrin stacking for sensitive analysis of neutral coumarins

A rapid, sensitive, environmental friendly dual preconcentration method by combining micro matrix solid-phase dispersion extraction with field-enhanced sample injection and micelle to cyclodextrin stacking has been developed for the determination of furocoumarins. Molecular sieve, KIT-6, was used as an adsorbent in micro matrix solid-phase dispersion process. The important parameters affecting off-line and online CE preconcentration efficiency were optimized. Under the optimal experimental conditions, all analytes showed good linearity (R² > 0.999). The LODs of notopterol, isoimperatorin, and imperatorin were 0.1 μg/mL, 1.2 mg/kg, and 1.0 mg/kg, respectively. Compared with the normal CE method, the enrichment times were up to 300. Moreover, Angelicae Dahuricae Radix was used as the mode of complex solid sample matrix to demonstrate the prospect of application of this methodology. The results showed the proposed strategy is promising for determining trace furocoumarins in complex matrix samples, which might be applied as a powerful and economic tool in monitoring illegal cosmetic adding.     

Sensitive determination of three aconitum alkaloids and their metabolites in human plasma by matrix solid‐phase dispersion with vortex‐assisted dispersive liquid–liquid microextraction and HPLC with diode array detection

A simple and sensitive method for determination of three aconitum alkaloids and their metabolites in human plasma was developed using matrix solid‐phase dispersion combined with vortex‐assisted dispersive liquid–liquid microextraction and high‐performance liquid chromatography with diode array detection. The plasma sample was directly purified by matrix solid‐phase dispersion and the eluate obtained was concentrated and further clarified by vortex‐assisted dispersive liquid–liquid microextraction. Some important parameters affecting the extraction efficiency, such as type and amount of dispersing sorbent, type and volume of elution solvent, type and volume of extraction solvent, salt concentration as well as sample solution pH, were investigated in detail. Under optimal conditions, the proposed method has good repeatability and reproducibility with intraday and interday relative standard deviations lower than 5.44 and 5.75%, respectively. The recoveries of the aconitum alkaloids ranged from 73.81 to 101.82%, and the detection limits were achieved within the range of 1.6–2.1 ng/mL. The proposed method offered the advantages of good applicability, sensitivity, simplicity, and feasibility, which makes it suitable for the determination of trace amounts of aconitum alkaloids in human plasma samples.     

Extraction of matrine from soil with matrix solid‐phase dispersion by molecularly imprinted polymers derived from lignin‐based Pickering emulsions

Molecularly imprinted polymers prepared by Pickering emulsion method with lignin as stable particle were used as dispersants in matrix solid‐phase dispersion, followed by ultra high performance liquid chromatography with tandem mass spectrometry to research the degradation behavior of matrine in soil. The molecularly imprinted polymers have regular morphology and uniform particles. Moreover, the adsorption experiments and the conditions of matrix solid‐phase dispersion were discussed. With the optimal conditions of matrix solid‐phase dispersion, the recoveries of matrine were 95.4–98.2%, relative standard deviations were 0.6–5.1%, and the detection limit was 5 ng/g. Moreover, the degradation behavior of matrine in soil was researched, it indicated the half‐life of matrine was 2.7–3.2 days, and it was an environmentally friendly botanical pesticide. The method was successfully applied to separate and analyze matrine in soil samples can decrease analysis time, save organic solvents, and improve the selectivity.