Matrix Solid-phase Dispersion Method Research Articles

Development of magnetic matrix solid phase dispersion method for the extraction of crystal violet and rhodamine B from sediments based on magnetic ZIF-8 and a deep eutectic solvent

A magnetic matrix solid phase dispersion (MSPD) method based on magnetic ZIF-8 (SDS@MZIF-8) and a deep eutectic solvent was developed and used to the extraction of crystal violet and rhodamine B in lake sediments. SDS@MZIF-8 was prepared and used as the extraction sorbent and dispersant in MSPD. The magnetic property of MZIF-8 facilitated the recovery of the extraction sorbent after the blending step. Hydrophilic deep eutectic solvents were prepared and used as efficient green dispersing solvents in MSPD. The use of magnetic sorbent in MSPD is simple and fast, eliminating some additional steps commonly used in the classical MSPD and shortening the extraction time. The parameters influencing the extraction efficiency were investigated and optimized. Under the optimized conditions, the intra- and inter-day relative standard deviations were less than 4.9 %. The linearity ranged from 2-400 µg g−1 with coefficients of determination higher than 0.9943. The detection and quantification limits of RB and CV varied between 0.3–0.5 μg g−1 and 1.0–1.8 μg g−1, respectively. Finally, the developed method was applied to the analysis of RB and CV in the sediment samples. The recoveries ranged from 93.2 to 107.3 % and the relative standard deviations ranged from 0.8 to 4.9 %. The results suggest a high potential use of the proposed method to determine the organic pollutants in solid samples. Compared with the conventional MSPD extraction technique, the developed method considerably reduced the sample and solvent consumption, offering important environmental benefits.

Optimization of a fast and sensitive method based on matrix solid-phase dispersion-LC-ms/ms for simultaneous determination of phthalates and bisphenols in mussel samples

Bisphenols and phthalates are wide classes of endocrine disrupting chemicals (EDCs) extensively used as additives in plastic products. In this study, a fast and reliable analytical method based on matrix solid-phase dispersion (MSPD) coupled with LC-MS/MS was developed and optimized for simultaneous determination of 8 bisphenols and 7 phthalates in raw mussel extract. The LC-MS/MS method was tested for linearity (R2), inter- and intra-day repeatability, limit of detection and quantification, both for matrix-free and matrix-matched solutions. The MSPD method was optimized in terms of ratio between sample and sorbent, and the type and quantity of the eluents in order to maximize the recoveries and to minimize matrix effects. The obtained recoveries (values between 75% and 113%), limits of detection (values between 0.048 and 0.36 µg kg−1), limits of quantification (values between 0.16 and 1.28 µg kg−1), repeatability (RSD% between 1.30% and 8.41%) and linearity (R2 > 0.998) were satisfactory and suitable for the determination of target micropollutants in food samples. In addition, the low solvent consumption and fast execution make this method ideal for routinely determinations of bisphenols and phthalates in mussels.

Assessing Matrix Solid-Phase Dispersion Extraction Strategies for Determining Bisphenols and Phthalates in Gilthead Sea Bream Samples

Microplastics (MPs) and nanoplastics (NPs) are widely spread in the environment, generating significant concern due to their potential impact on environmental health. Marine species usually ingest plastic fragments, mistaking them for food. Many toxic compounds, such as plastic additives that are not chemically bound to the plastic matrix, can be released from MPs and NPs and reach humans via the food chain. This paper highlights the development and validation of a straightforward solid–liquid extraction clean-up procedure in combination with a matrix solid-phase dispersion method using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) detection, enabling facile, precise, and reliable identification and quantitation of a total of six bisphenols and phthalates in gilthead sea breams. Under the optimized conditions, the developed method showed good linearity (R2 > 0.993) for all target compounds. The recoveries obtained were between 70 and 92%. The relative standard deviations (RSDs) for reproducibility (inter-day) and repeatability (intra-day) were less than 9% and 10%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the target compounds ranged from 0.11 to 0.68 µg/kg and from 0.37 to 2.28 µg/kg, respectively. A new, efficient extraction methodology for the determination of BPA, BPS, BPF, DBP, DEP, and DHEP in gilthead seabream has been optimized and validated.

Miniaturized centrifugation accelerated pipette-tip matrix solid-phase dispersion based on poly(deep eutectic solvents) surface imprinted graphene oxide composite adsorbent for rapid extraction of anti-adipogenesis markers from Solidago decurrens Lour

Overweight and obesity are the causes of many diseases and have become global "epidemics". Research on natural active components with anti-adipogenesis effects in plants has aroused the interest of researchers. One of the most critical problems is establishing sample preparation and analytical techniques for quickly and selectively extracting and determining the active anti-adipogenesis components in complex plant matrices for developing new anti-adipogenic drugs. In this study, a new poly(deep eutectic solvents) surface imprinted graphene oxide composite (PDESs-MIP/GO) with high selectivity for phenolic acids was prepared using deep eutectic solvents as monomers and crosslinkers. A miniaturized centrifugation-accelerated pipette-tip matrix solid-phase dispersion method (CPT-MSPD) with PDESs-MIP/GO as adsorbent, coupled with high-performance liquid chromatography, was further developed for the rapid determination of anti-adipogenesis markers in Solidago decurrens Lour. (SDL). The established method was successfully used to determination anti-adipogenesis markers in SDL from different regions, with the advantages of accuracy (recoveries: 94.4-115.9%, RSDs≤9.8%), speed (CPT-MSPD time: 11min), selectivity (imprinting factor: ∼2.0), and economy (2mg of adsorbent and 1mL of solvents), which is in line with the current advanced principle of "3S+2A" in analytical chemistry.

Green approaches with amino acids-based deep eutectic solvents (AADES) for determining As in medicinal herbs by ICP-MS

In this work, an innovative ultrasound-assisted matrix solid-phase dispersion (UA-MSPD) method and microwave-assisted extraction (MAE) were applied with amino acids-based deep eutectic solvents (AADES) for the extraction of arsenic (As) from medicinal herbs. Multivariate optimization by Doehlert design (DD) was performed to determine the optimal experimental conditions. The effects of temperature (TP), time (TM), and sample-solvent ratio (SSR) were evaluated, and the optimized conditions were 50 °C, 60 min, and 10:1 mg mL−1 for UA-MSPD and 100 °C, 40 min, and 40:1 mg mL−1 for MAE, employing AADES 2 (β-alanine, citric acid, and water), where the hydroxyl and carboxyl groups of the citric acid structure favored formation of a chelate complex with the analyte. AADES 3 (β-alanine, xylitol, and water) was effective for MAE, while AADES 1 (β-alanine, malic acid, and water) proved to be inefficient for As extraction. The parameters of the analytical methods were evaluated using certified reference materials. The accuracy, based on percentage recovery, was in the range 77–101 %, while the limits of detection and quantification were in the ranges 0.010–0.039 mg kg−1 and 0.011–0.130 mg kg−1, respectively. The analytical curves presented R2 > 0.99. The proposed methods were shown to be environmentally friendly, based on the Analytical Eco-Scale and RGB 12 procedures. Both optimized methods were applied for the determination of As in commercial medicinal herbs (0.059–0.101 mg kg−1), with the values obtained being within the maximum daily intake limit established by the World Health Organization (WHO). It should be noted that there are no previous reports in the literature concerning the application of a sample preparation method using AADES, employing their solid precursors, with no requirement for prior solvent synthesis, as proposed here in the case of the UA-MSPD method.

C18-modified halloysite as a novel sorbent in matrix solid-phase dispersion for the extraction of bisphenol A and diethylstilbestrol from human placenta.

In the current study, the C18-modified halloysite was fabricated via silylation reaction and subsequently used as sorbent in matrix solid-phase dispersion (MSPD) for the extraction of bisphenol A and diethylstilbestrol from human placenta, followed by high-performance liquid chromatography-tandem mass spectrometry analysis. The as-prepared sorbent was characterized by scanning electron microscopy, energy-dispersive spectrometry, Fourier transform infrared spectroscopy, X-ray diffraction, and thermo-gravimetric analysis. Varied parameters such as methanol concentration in wash solvent, pH and salt concentration in elution solvent, elution volume, and mass ratio of sample to sorbent were optimized. The adsorption capacities of bisphenol A and diethylstilbestrol on the developed C18-modified halloysite were 6.3 and 14.2mgg-1, respectively, higher than those on the commercial C18 silica gel. Under the optimal condition, the average recoveries of bisphenol A and diethylstilbestrol by MSPD varied from 91.0 to 106.0%, and the relative standard deviations were less than 10.6% for human placenta samples. The limits of detection in the human placenta were 0.2μgkg-1 for bisphenol A and diethylstilbestrol. The simple C18-modified halloysite-based MSPD method holds great potential for the determination of trace bisphenol A and diethylstilbestrol in the human placenta and other tissues of pregnant women with high sensitivity, accuracy, and reliability.

Boron nitride nanosheet-assisted matrix solid-phase dispersion microextraction of alkaloids from lotus plumule by high-performance liquid chromatography coupled with ultraviolet detection and ion mobility quadrupole time-of-flight mass spectrometry.

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 (50mg), and extraction time (2min). Under the best conditions, 50mg of sample powder was dispersed with 50mg of BNNSs, the grinding time was 120 s, the mixed powder was eluted with 200μL of methanol, and good linearity (r2 >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 15.00ng/mL, and the limits of quantitation were 8.47 to 50.00ng/mL. The proposed method was successfully applied for the determination of liensinine, isoliensinine, and neferine in lotus plumule.

Performance of different extraction methods for paralytic shellfish toxins and toxin stability in shellfish during storage.

Accurate analysis of paralytic shellfish toxins (PSTs) in shellfish is important to protect seafood safety and human health. In this study, the performance of different extraction protocols for PSTs from scallop tissues is compared and discussed, including regular extraction solvents hydrochloric acid (HCl) and acetic acid (AcOH) followed by heating and solid-phase extraction (SPE) purification, and a novel technique of matrix solid-phase dispersion (MSPD) without heating. The possible conversion of C1/2 and GTX2/3 standards after heating, and the stability of PSTs in wet scallop tissues stored at -20°C for a 6-month period are also explored. Results showed that the MSPD technique could effectively mitigate matrix interference, but its recoveries of PSTs were significantly lower than those of the HCl and AcOH extraction methods followed by carbon SPE purification. The molar concentrations of M-toxins obtained by the MSPD method were generally lower than those analyzed by the HCl and AcOH extraction methods, which demonstrated a weak chemical conversion of C1/2 and GTX2/3 due to the heating process. Most of the PSTs were relatively stable in scallop tissues during 1-month storage at -20°C, while the concentrations of PSTs in scallop tissues obviously changed after 6 months due to the degradation and transformation of PSTs during long-term storage at -20°C. This work helps improve our understanding of the performance of different extraction methods and the stability of PSTs in scallop tissues stored at -20°C.

Boron Nitride Nanoplates-Assisted Matrix Solid-Phase Dispersion Microextraction of Alkaloids from Plant Tea by Ultrahigh-Performance Liquid Chromatography Coupled with Ion Mobility Quadrupole Time-of-Flight Mass Spectrometry

Boron nitride nanoplates-assisted matrix solid-phase dispersion method was established to microextract the alkaloids from medical plant. The target compounds were identified by ultrahigh-performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass. During experiment process, several important parameters including the type of dispersant, the amount of dispersant, the grinding time and the type of elution solvent were optimized. At last, the boron nitride nanoplatelets was chosen as best dispersant and the microcosmic morphologies of it were identified by scanning electron microscope (SEM) and transmission electron microscope (TEM). Due to the special property of boron nitride nanoplatelets the cost of this experiment was saved greatly especially in elution volume (200 μL), sample amount (50 mg) and extraction time (2 min). With the best condition, good linearity (r2>0.9993) and satisfactory recoveries (80%-100%) were obtained. The inter-day and intra-day precision were acceptable with the RSDs lower than 1.9% and 4.84% respectively. The limits of detection were ranged from 2.54 to 15 ng mL-1 and the limits of quantitation were 8.47 to 50 ng mL-1. At present, the proposed method has been successfully applied for the determination of liensinine, isoliensinine and neferine in lotus plumule.

In situ antioxidation-assisted matrix solid-phase dispersion microextraction and discrimination of chiral flavonoids from citrus fruit via ion mobility quadrupole time-of-flight high-resolution mass spectrometry

A simple and sensitive in situ antioxidation process assisted with a matrix solid-phase dispersion method for extracting chiral flavonoids in citrus fruit was established, and samples were further analyzed using ion mobility quadrupole time-of-flight high-resolution mass spectrometry. The collision cross-sections of the target compounds were studied using single-field and stepped-field methods. The optimal conditions were obtained using 30 mg of C18 as a dispersant, methanol as an elution solvent and 0.6 mM 1,1-diphenyl-2-picrylhydrazyl (DPPH) as a radical solution. Additionally, the method showed satisfactory limits of detection (3.70–6.52 ng/mL) and good recoveries (96.78–104.67%) for four flavonoids in citrus fruit. The IC50 values of DPPH radical-scavenging activities ranged from 817.8 to 981.55 μg/mL for tested samples. The method was a good alternative for the microextraction and determination of antioxidant capacity and chiral differentiation of narirutin, naringin, hesperidin and neohesperidin in citrus fruit.

Rapid and Sensitive Method for Extraction of Plicosepalus acacia with Determination of Its Main Polyphenolic Compounds Using Validated HPLC.

Matrix solid phase dispersion (MSPD) trailed by HPLC is a quick and fruitful technique utilized for fortitude of flavonoids such as Catechin, Kaempferol, Quercetin, and Rutin existing in P. acacia. The trial parameters that influenced the extraction potential (comprising the mass ratio of sample to the dispersant, nature of dispersant, and the nature of elution solvent and its volume) were examined and optimized. These MSPD optimized parameters regulated are as follows: 8 mL of methanol was utilized as elution solvent, silica gel/sample mass ration was selected to be 2 : 1, and dispersing sorbent was silica gel. The technique retrievals were regulated to be “from 96.87 to 100.54%” and the RSDs from 1.24 to 4.45%. The product of extract obtained by MSPD method was larger than that of other methods, i.e., sonication extraction or traditional reflux with lessened necessities on time, sample, and solvent.

Simultaneous determination of febantel, fenbendazole, oxfendazole and oxfendazole sulfone in livestock by matrix solid phase dispersion extraction technique and HPLC

Febantel, fenbendazole, oxfendazole and oxfendazole sulfone in livestock products were simultaneously extracted by traditional and matrix solid phase dispersion (MSPD) method, and then analyzed by high performance liquid chromatography (HPLC). In the traditional method, four benzimidazoles were extracted with acetonitrile under basic conditions, partitioned with n-hexane, and cleaned by a Sep-Pak C18 cartridge. In the MSPD method, samples were blended with Bondesil-C18, and the mixture was packed in a filtration column. This column was connected in tandem with an alumina N cartridge and eluted with acetonitrile. These benzimidazoles were determined by HPLC with a photodiode array detector. Recovery tests of benzimidazoles by these two methods were performed at three spike levels. In the traditional method, febantel was found to be unstable during the sample preparation. Average recoveries of febantel ranged from 72.3 to 81.6%. Average recoveries at low concentration (0.04 ppm) of fenbendazole ranged from 75.0 to 88.3%, while the remaining benzimidazoles ranged from 80.3 to 108.7%. The coefficients of variation of intra-day and inter-day assays were lower than 6.95 and 12.12%, respectively. Average recoveries of the MSPD method ranged from 80.2 to 109.6%. The coefficients of variation of intra-day and inter-day assays were lower than 4.47 and 7.89%, respectively. The detection limits for benzimidazoles were 0.010-0.020 ppm for the traditional method and 0.025-0.050 ppm for the MSPD method. The MSPD method minimized sample preparation time and solvents, and the analyte was stable during the analytical procedure with high recoveries. The MSPD method is suggested for use in routine analysis of benzimidazoles in livestock produts.

Post-harvest treatment of carbendazim in Chinese chives using TiO2 nanofiber photocatalysis with different anatase/rutile ratios

Carbendazim residues in Chinese chives were treated by photocatalysis using the following three electrospun TiO2 nanofibers: TTiP/PVP, TTiP/PVAc, and TBOT/PVP. The as-spun fibers were calcined at 500–650 °C to achieve anatase/rutile (A/R) ratios of 100:0, 80:20, 70:30, 50:50, and 30:70. The obtained anatase crystallite sizes were in the range of 13.9–28.1 nm, while the rutile crystallite sizes were 21.1–30.6 nm. The experiments were conducted in glass reactors. These were filled with water and each type of the fiber and irradiated from above by black light lamps for 5 min. Then, 50 g of the samples of Chinese chives was immersed for 5, 15, 30, and 60 min. Carbendazim in the chives was extracted using the matrix solid-phase dispersion (MSPD) method and analyzed using UHPLC. The ˙OH formation from each fiber type was investigated using the coumarin fluorescent probe method. An A/R ratio of 70:30 yielded the highest ˙OH formation, as well as the greatest carbendazim degradation. Rutile plays a crucial role in inhibition of electron-hole recombination and ˙O2− stabilization. The degradation efficiencies for carbendazim from TTiP/PVP, TTiP/PVAc, and TBOT/PVP fibers after a 60-min treatment were 98.6–99.5%, 91.2–97.1%, and 99.5–99.9%, respectively. The TTiP/PVP and TBOT/PVP fibers produced levels of retained carbendazim in the chives that were within EU maximum residue limits of 0.1 mg/kg. The thermal stability of the TTiP/PVAc fiber limited ˙OH formation and carbendazim degradation.

Microextraction assisted multiple heart-cutting and comprehensive two-dimensional liquid chromatography hyphenated to Q-TOF/MS for the determination of multiclass compounds from Dendrobium species

Chromatographic separation and determination of closely related classes are one of the most difficult tasks in the analysis of medicinal plants. In addition, two-dimensional ultra-high performance liquid chromatography (2DLC) has enormous potential and become a significant tool for enhancing peak capacity, selectivity and sensitivity. Workflows based on multiple heart-cutting (MHC) and comprehensive 2DLC (LC × LC) hyphenated to quadrupole time-of-flight mass spectrometry (Q-TOF/MS) were described that allow to identify and separate the analytes in Dendrobium species. Three Dendrobium genus were Dendrobium officinale Kimura et Migo, Dendrobium nobile Lindl and Dendrobium chrysotoxum Lindl. In this study, excellent selectivity, resolution, and peak shape were obtained through combining reversed-phase SB C18 column (2.1 × 100 mm, 1.8 μm) in the first dimension with 3.0 × 50 mm Poroshell 120 Bonus column (1.8 μm particle size) in the second dimension (2D), together with the application of synchronized mode in both dimensions. The matrix solid phase dispersion method was applied to extract Dendrobium species and 31 compounds were characterized and separated within 40 min. In terms of 2D flow rate and separation, LC × LC mode was faster than MHC mode. However, too high 2D flow rate would exacerbate the damage to the column in the LC × LC mode. MHC mode was used to genernally separate and analyze specific parts of the sample, otherwise it would take too much time. In short, MHC and LC × LC coupled with Q-TOF/MS method was a powerful technique and shown to be applicable for the analysis and determination of trace compounds in Dendrobium genus extracts and could be easily expanded to other complex mixtures.

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 1min. The exhaustive elution of targets was achieved by 200µL methanol/water (9:1) containing 150mM 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.

A Beta/ZSM-22 Zeolites-Based-Mixed Matrix Solid-Phase Dispersion Method for the Simultaneous Extraction and Determination of Eight Compounds with Different Polarities in Viticis Fructus by High-Performance Liquid Chromatography.

Viticis Fructus (VF) was named Manjingzi as a commonly used traditional Chinese medicine (TCM) targeting various pains and inflammation for more than 2000 years. To guarantee the quality of Viticis Fructus, a simple, quick and eco-friendly Beta/ZSM-22 zeolites-based-mixed matrix solid-phase dispersion method (B/Z-MMSPD) was established for simultaneous extraction and determination of eight compounds (two phenolic acids, two iridoid glycosides, vanillin and three flavonoids) with different polarities from Viticis Fructus by high performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Beta and ZSM-22 were mixed as the sorbent. Water, tetrahydrofuran and methanol were blended with certain ratio as the eluent. Several parameters including types of sorbents, mass ratio of Beta to ZSM-22, mass ratio of matrix to sorbent, grinding time, types, concentration and volume of eluent were optimized. The recoveries of eight analytes were within the range of 95.0%–105% (RSDs ≤ 4.13%). The limits of detection and limits of quantitation ranged from 0.5 to 5.5 μg/g and from 1.5 to 16 μg/g, respectively. Compared to the traditional extract methods, it was a simple, rapid, efficient and green method. The results demonstrated that a simple, rapid, efficient and green B/Z-MMSPD was developed for the simultaneous extraction and determination of eight target analytes with different polarities for quality control of Viticis Fructus.

A chitosan solution-based vortex-forced matrix solid phase dispersion method for the extraction and determination of four bioactive constituents from Ligustri Lucidi Fructus by high performance liquid chromatography

A simple and efficient sample preparation method to extract four bioactive compounds (echinacoside, specnuezhenide, oleuropein and nuezhenoside G13) from Ligustri Lucidi Fructus was established by vortex-forced matrix solid phase dispersion (VFMSPD) method. Chitosan solution was applied as green eluent in this procedure and Celite AZO was employed as dispersant. High performance liquid chromatography (HPLC) equipped with ultraviolet (UV) detector was used to analyze the target analytes. The best result of the investigation was obtained with Celite AZO as dispersant, sample/ dispersant ratio as 1:1, grinding for 2 min, 1 mL high-viscosity chitosan solution (0.5 mg mL−1) used as the elution reagent and vortex mixing for 1.5 min. The method exhibit a good linearity for the analytes (r2 > 0.999). The absolute recoveries of the four target compounds in Ligustri Lucidi Fructus ranged from 90.7% to 98.8% and the relative recoveries of the target compounds ranged from 99.2% to 102% (RSD ≤ 3.4%), which were obtained by the final optimization method. Consequently, the newly developed chitosan solution-based vortex-forced matrix solid phase dispersion (MSPD) combined with HPLC could be efficiently applied to extract and analyze the target compounds in Ligustri Lucidi Fructus samples.

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, 0.5mL 100mM 1-dodecyl-3-methylimidazolium hydrogen sulfate as the extraction solvent, 2:1 of sample/sorbent ratio, grinding for 2min and vortexing for 60s. 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 0.06-1.25μg/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.

Evaluation of MCM-41 and MCM-48 mesoporous materials as sorbents in matrix solid phase dispersion method for the determination of pesticides in soursop fruit (Annona muricata)

The MCM-41 and MCM-48 mesoporous materials were tested for extraction of thiamethoxam, thiacloprid, thiophanate-methyl, teflubenzuron, and bifenthrin from the fruit of soursop (Annona muricata), using liquid chromatography with ultraviolet diode array detection as the analysis technique. Extractions performed at one fortification level (0.5 mg kg−1, n = 3) resulted in recoveries in the ranges 75–106% and 76–95% for MCM-41 and MCM-48, respectively, with relative standard deviations (n = 3) ranging from 5 to 9%. The detection and quantification limits for the pesticides studied were in the ranges of 0.02–0.06 mg kg−1 and 0.05–0.10 mg kg−1. The developed method was linear over the concentration range tested (0.01–5 mg kg−1), with correlation coefficients of between 0.9620 and 0.9999. Comparison of the mesoporous materials and a conventional sorbent (Florisil) revealed a similar performance for the pesticides.

In situ chemical reaction-based matrix solid-phase dispersion of hydrophilic and hydrophobic compounds from Scutellariae radix

An in situ chemical reaction-based matrix solid-phase dispersion (MSPD) method was developed for the extraction of the hydrophilic and hydrophobic compounds in the plant Scutellariae radix. In this study, target analytes were hydrophilic and hydrophobic compounds in the S. radix, which included baicalein, wogonin, baicalin and wogonoside. Among these, baicalin and wogonoside were hydrophilic compounds while baicalein and wogonin were hydrophobic compounds. Several experimental conditions were discussed and optimized, including the type of the dispersant, the amount of the dispersant, the extraction time, the grinding time and the pH value. The optimized type of the dispersant was determined to be sodium bicarbonate and the amount was chose to be 20 mg. The optimized extraction time was 5 min, and the grinding time was 2.5 min at a pH of 7.5. The developed method simplified the pretreatment of extraction, reduced the use of samples and dispersants, and used pure water instead of organic solvents. In addition, the method revealed good linearity (r2 ≥ 0.9978) for the target analytes, with the limits of detection from 12.52 to 59.76 μg·kg−1, the limits of quantification from 41.72 to 199.20 μg·kg−1 and the method quantification limits from 0.124 to 0.292 μg·kg−1. Moreover, the recovery values of the tested compounds ranged from 86.0% to 104%. The MSPD method was successfully employed for the extraction of baicalein, wogonin, baicalin and wogonoside in S. radix.