Vortex-assisted Extraction Research Articles

Covalent organic framework composite hydrogel sorbent beads for vortex-assisted dispersive miniaturized solid phase extraction of parabens and synthetic phenolic antioxidants in foodstuffs

A covalent organic framework composite hydrogel sorbent beads was fabricated for the vortex-assisted dispersive miniaturized-solid phase extraction and determination of parabens and synthetic phenolic antioxidants from food matrices. The covalent organic framework was entrapped into alginate hydrogel beads. This composite sorbent effectively adsorbs analytes through hydrophobic, π-π and hydrogen bonding interactions. Under optimal extraction conditions, the developed method demonstrated good linearity from 1.00 to 100 µg kg−1 for methyl paraben and 2.00 to 100 µg kg−1 for tertiary butylhydroquinone, propyl paraben, butyl paraben and butylated hydroxyanisole. Limits of detection ranged from 0.25 to 0.50 µg kg−1. The developed sorbent was applied to the extraction of parabens and synthetic phenolic antioxidants from tomato paste, mayonnaise, infant milk powder and coffee creamer samples. The analytes were separated and quantified by high-performance liquid chromatography, achieving recoveries ranging from 89 to 98 % with RSDs lower than 7 %. The vortex-assisted extraction approach was efficient, and the fabricated sorbent could be reused for up to eight cycles. The greenness of the methodology was also evaluated.

Nano temperature-switchable supramolecular solvent: Preparation, characterization and application in efficient extraction and enrichment of phytochemicals

In this study, a nano temperature-switchable supramolecular solvent (NTS-SUPRAS) system was designed, prepared and characterized for efficient extraction and enrichment of phytochemicals, the extraction mechanism was also investigated. The NTS-SUPRAS was synthesized by natural deep eutectic (NADES), 1,2-Propanediol and water, then the ternary phase diagrams were plotted according to their mass fractions. Dynamic light scattering (DLS), conductivity and FT-IR were used to characterize the solvent, and an exciting discovery was the nanoscale of NTS-SUPRAS. The particle size of its reverse micelles self- aggregated was positively correlated to the water content, which was increased from 3.8 nm to 77.9 nm as the water content increased from 5 % to 20 %. Temperature-switchable of NTS-SUPRAS was proved by the appearance of phase separation when regulate temperature from 25 °C to 10 °C. Then, six phytochemicals in Cajanus cajan(Linn.) leaves were efficiently extracted and enriched by vortex-assisted extraction. The extraction factors such as solid–liquid ratio, vortex time, NADES content and water content were optimized using the one-factor optimization method and response surface analysis to obtain the optimal extraction conditions. The results showed that the extraction efficiency of NTS-SUPRAS was 1.18–2.32 folds higher than that of traditional solvents for different polar substances, and the total extraction yield could be reached 21.13 mg/g. The phytochemicals were highly recovered by temperature-switching and macroporous adsorption resin with a recovery rate up to 98.6 %, and the reusability of NTS-SUPRAS could still keep at 90.43 % of the initial one after three cycles. Finally, the extraction mechanism of NTS-SUPRAS was investigated using density functional theory (DFT), founding that the hydrogen bonding between NTS-SUPRAS and the phytochemicals was attributed to the high extraction rate. This nano temperature-switchable supramolecular solvent has the advantages of green, low cost, simple preparation, high extraction rate, easy recycling and good reusability, which is suitable for industrialized application and production. In addition, the nanoscale and the temperature-switchable characteristics also provide new prospects for high-value utilization of phytochemicals.

Extraction of Antioxidants from Brown Macroalgae Fucus spiralis.

In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted extraction. The extracts were analyzed for their total phenolic content (TPC) and their antioxidant activity, and evaluated through the 2,2-difenil-1-picrilhidrazil (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Ultrasonic probe-assisted extraction yielded the highest values of TPC (94.78-474.16 mg gallic acid equivalents/g extract). Regarding the antioxidant activity, vortex-assisted extraction gave the best DPPH results (IC50 1.89-16 µg/mL), while the highest FRAP results were obtained using the Ultra-Turrax® homogenizer (502.16-1188.81 μmol ascorbic acid equivalents/g extract). For each extraction method, response surface methodology was used to analyze the influence of the experimental conditions "extraction time" (t), "biomass/solvent ratio" (R), "solvent" (S, water % in water/ethanol mixture), and "pressure" (P) on TPC, DPPH, and FRAP of the F. spiralis extracts. In general, higher TPC content and higher antioxidant capacity (lower IC50 and higher FRAP) were obtained with higher R, t, and P, and lower S (higher ethanol %). The model regarding the combined effects of independent variables t, R, and S on the FRAP response values for vortex-assisted extractions best fitted the experimental data (R2 0.957), with optimal extraction conditions of t = 300 s, R = 50 g, and S = 25%.

Development of a vortex-assisted switchable-hydrophilicity solvent-based liquid phase microextraction for fast and reliable extraction of Zn (II), Fe (II), Pb (II), and Cd (II) from various baby food products

This manuscript describes the development of a novel liquid phase microextraction (LPME) method for the extraction and determination of Zn (II), Fe (II), Pb (II), and Cd (II) in various infant/baby food and supplements products. The method is based on vortex-assisted extraction combined with a switchable-hydrophilicity solvent (SHS) sample preparation. The SHS, which undergoes reversible phase changes triggered by pH change, enables selective extraction and easy phase separation. A flame atomic absorption spectroscopy was used in the final determination step. Optimization studies revealed, that the optimal pH of the sample solution (after digestion) during analytes extraction is 5.5. A l-proline is added to the sample (375 mM) to ensure the complexation of the target metal cations. After the complexation step, 750 µL of SHS - a N, N-Dimethylcyclohexylamine along with 0.9 mL of 2 M of acetic acid solution is added (hydrophilicity switch-on stage) and mixed manually to obtain a homogeneous solution. In the last stage, 0.45 mL of 10 M NaOH solution (hydrophilicity switch-off stage) is added to the sample solution and a vortex for 100 s is applied to ensure the effective extraction and separation of the complex containing the analytes. At this stage, a cloudy solution is immediately obtained. Finally, the effective phase separation is obtained at the centrifugation step (4000 rpm for 2 mins). The method limit of detection was as 0.03, 0.009, 0.6, and 0.2 ng/L for Zn (II), Fe (II), Cd (II), and Pb (II) respectively with RSD% below 2.0 %. The analysis of certified reference materials and real samples proved the full applicability of the method for routine analysis, contributing to the field of heavy metal analysis and ensuring the safety of baby products. According to the AGREE methodology, this method can be named as green analytical chemistry method with a score of 0.77.

A heteropore covalent organic framework for highly selective enrichment of aryl-organophosphate esters in environmental water coupled with UHPLC−MS/MS determination

The identification of an increasing number of aryl organophosphate esters (aryl-OPEs) in environmental samples has led to growing attention recently. Due to the potential adverse effects on human health and environment, development of new analytical methods for sensitive and selective determination of aryl-OPEs in complex matrices is urgently needed. Here, a novel analytical method for the identification and determination of trace amounts of aryl-OPEs in water samples is developed by using melamine sponge@heteropore covalent organic framework (MS@HCOF) based on vortex-assisted extraction (VAE) prior to UHPLC−MS/MS analysis. The MS@HCOF was rationally designed and synthesized through an in-situ growth strategy and exhibited superior selectivity toward aryl-OPEs compared with that of MS@single-pore COF (MS@SCOF) due to steric effect. A systematic optimization was conducted on important parameters of VAE, resulting in the successful extraction of nine aryl-OPEs in just 6 min. Under optimized conditions, the limits of detection (S/N = 3) and quantification (S/N = 10) were within the ranges of 0.001−0.027 and 0.005−0.091 ng/L for nine aryl-OPEs, respectively. The validated method was proven applicable to real water samples, i.e., the recoveries were 65.3−119.5 % for seawater, 59.4−112.9 % for effluent, and 76.0−117.4 % for tap water. Furthermore, the adsorption mechanisms were explored through density functional theory (DFT) calculations. DFT results revealed that a notable selective enrichment capacity of MS@HCOF towards aryl-OPEs stems from π-π conjugation and hydrogen bonding. The established method benefits from the advantages of high selectivity and sensitivity for the ultra-trace determination of aryl-OPEs.

Determination of process contaminants 2- and 3-MCPD esters and glycidyl esters in palm-based glycerol by indirect analysis using GC-MS

Esters of 2- and 3-monochloropropanediol (2-MCPDE, 3-MCPDE) and glycidol (GE) are regarded as process contaminants that are found in refined vegetable oils and oil-based foods. Since glycerol is produced during fat splitting, saponification and biodiesel production, it is important to have methods for determining contaminants that might be formed during these processes. Due to the use of glycerol as a food additive, data on the presence of compounds of toxicological concern, including 3-MCPD, are of interest. This study focuses on modifying the indirect analysis of 2-MCPDE, 3-MCPDE and GE using GC-MS based on the AOCS Official Method Cd 29a-13, validating the modified method, and quantifying 2-MCPDE, 3-MCPDE and GE in glycerol. The AOCS Cd 29a-13 method was modified at the initial stage of sample preparation in which the targeted esters were extracted from glycerol by vortex-assisted extraction before sample analysis. This modification was performed based on the polarity of all compounds involved. The calibration functions for all analytes were fitted to linear regression with R 2 above 0.99. Limits of detection (LOD) 0.02, 0.01 and 0.02 mg kg−1 were obtained for 2-MCPDE, 3-MCPDE and GE, respectively. Spiked glycerol with 3-MCPDE and 2-MCPDE (0.25, 0.51 and 1.01 mg kg−1) and GE (0.58, 1.16 and 2.32 mg kg−1) were used for recovery and precision measurements. Recoveries of 100-108%, 101-103%, and 93-99% were obtained for 2-MCPDE, 3-MCPDE and GE, respectively. Acceptable precision levels with relative standard deviations ranged from 3.3% to 8.3% were obtained for repeatability and intermediate precision. The validated method was successfully applied for the analysis of the target compounds in refined glycerol from commercial plants, which showed that 2-MCPDE, 3-MCPDE and GE levels in the analysed samples were below the detection limit.

Novel natural deep eutectic solvent-based supramolecular solvents designed for extracting phytochemicals from pigeon pea leaves and its scale-up and recovery process

In this study, a novel green natural deep eutectic solvent-based supramolecular solvent/equilibrium solution (NADES-SUPRAS/EqS) system was designed. The microstructure and formation processes were characterized, revealing the formation and extraction mechanism of this novel solvent. In combination with vortex-assisted extraction, NADES-SUPRAS/EqS was used to efficiently extract and enrich representative active ingredients of different polarities in Cajanus cajan (Linn.) Millsp leaves. The influencing factors, including auxiliary extraction methods, the type of NADES, the proportion of NADES and ethanol for synthesis, the solid-to-liquid ratio, and the vortex time, were then adjusted utilizing single-factor optimization and response surface methodology. Under ideal extraction parameters, the extraction rates obtained were higher than other conventional organic solvents and had an excellent enrichment effect with only 90 s of vortex-shaking. Ultimately, an integrated multi-stage counter-current extraction and recovery unit was developed, capable of reducing costs and easily recovering solvents and target compounds, exploring the possibility of large-scale applications in the industry. A complete set of extraction, isolation, and recovery from plant material to chemical components offers a new perspective for the development of a high-value industry for plant secondary metabolites.

Vortex-assisted dispersive solid phase microextraction using Fe3O4/FeOOH magnetic nanocomposites for high-performance thin-layer chromatographic determination of zolmitriptan in rabbit plasma samples

In this work, a fast, versatile, and convenient dispersive solid-phase micro-extraction (DSPME) method is combined with a spectro-densitometric technique for the analysis of zolmitriptan (ZOLM) in biological fluids. Fe3O4/FeOOH magnetic nanocomposites (MNCs) were prepared by a co-precipitation method in aqueous solutions and utilized subsequently as a sorbent in DSPME. By coupling DSPME with high-performance thin-layer chromatography (HPTLC) with fluorescence detection, the preconcentration and determination of (ZOLM) in presence of metoclopramide (MET) and paracetamol (PARA), which are prescribed as an adjuvant therapy with ZOLM, was accomplished. Adsorption capability was assessed using both Langmuir and Freundlich adsorption isotherm models. The adsorption data was fitted to Langmuir adsorption isotherm model as reflected by high determination coefficient (R2 = 0.9944). Moreover, adsorption kinetics was assessed by pseudo-first and pseudo-second order kinetic models. The data was fitted to pseudo-second order kinetics, which proves that ZOLM interaction with the adsorbent is a chemisorption process. Surface complexation with MNCs was suggested to explain the pH dependence of ZOLM sorption. The key parameters of extraction and desorption steps (including pH, extraction time, sample volume, magnetic adsorbent amount, and desorption circumstances) were evaluated. Optimized conditions for solid phase microextraction of ZOLM were pH 2.9, 5.0 mg Fe3O4/FeOOH MNCs, 15 min vortex-assisted extraction time and 3 × 200 μL of methanol: 33% ammonia; 4:1 as eluent. The analysis was achieved using ACN: dichloromethane: 33% ammonia (22.5: 6.0: 1.5, v/v/v) as a mobile phase and the fluorescence detection was carried out at 223 nm. The proposed DSPME method was successfully applied for trace quantification of ZOLM in rabbits’ plasma (n = 6) after oral administration with a linearity range of 50.0 – 400.0 ng mL−1 (R2 = 0.9931), a detection limit of 12.0 ng mL−1 and extraction recovery of 97.27–99.89% with an RSD < 2% (n = 9). Moreover, the selectivity of the proposed approach for analysis of ZOLM in the presence of MET and PARA is demonstrated.

Efficient Vortex-assisted Extraction of Phorbol Esters from Jatropha Leaves and Correlation Between Leaves and Seeds in Phorbol EstersContent

ABSTRACT This work aimed to optimise and validate the vortex-assisted extraction with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) method to quantify phorbol esters (PEs) in Jatropha leaves. Additionally, to evaluate the correlation between PEs content in leaves and seeds. The results of PEs content were expressed as equivalent of the major Jatropha phorbol ester, 12-deoxy-16-hydroxyphorbol-4'-[12',14'-butadienyl]-6'-[16',18',20'-nonatrienyl]-bicyclo[3.1.0]-hexane-(13-O)-2'-[carboxylate]-(16-O)-3'-]8'-butenoic-10']ate (DHPB) . One-variable-at-time strategy and 25-1V factorial fractional design were employed to determine the effects of solvent type, volume, stirring frequency, extraction time and cycles on yield. The quantification was performed using HPLC-UV. The optimum conditions were three extractions with 2% tetrahydrofuran:dichloromethane (1:1) in methanol (THF:DCM/MeOH). The sample:solvent ratio was 1 mg:25 μL, and the vortex stirring was 2200 rpm for 5 minutes. The method showed good linearity (R2 0.999), recoveries (97 to 105%), selectivity and repeatability (RSD 1.93-7.95%). In addition, good limits of detection and quantification of 2.19 and 6.65 ng μL"1, respectively, were noted. DHPB content in leaves and seeds ranged from 0.01 to 0.38 mg g"1 and 0.41 to 1.82 mg g"1, respectively. There is a statistically significant and positive linear relationship between leaves and seeds for DHPB content. These results may have practical application in analysing and predicting the amount of PEs in Jatropha leaves for environmental safety studies and the selection of better varieties for genetic improvement. Keywords: correlation, Jatropha leaves; Jatropha seeds; phorbol esters; vortex-assisted.

Vortex Assisted Extraction for Propyl Paraben Analysis in Cosmetics

Propylparaben is an ester of para-hydroxybenzoic acid and commonly used as a preservative in the cosmetics, pharmaceuticals and food products. However, several recent reports demonstrated that paraben possesses an estrogenic activity and causes cancer for the consumer. Therefore, the extraction of propylparaben from cosmetics requires method that is easy, fast, user-friendly and accurate reproducible result. Conventional techniques such as liquid-liquid extraction (LLE) show some disadvantages such as the use of a large amount of solvent and time-consuming. Therefore, this present study aims to apply vortex assisted extraction (VAE) in determining the concentration of propylparaben in cosmetic samples and analyse using ultraviolet spectroscopy (UV-Vis). From the results, the calibration curve was found in the range of 0.2-1.0mg/L with a regression coefficient, r2=0.9932 and relative standard deviation (RSD) less than 1%. The limit of detection (LOD) and quantification (LOQ) for VAE was 0.090mg/L and 0.302mg/L, respectively. Operating parameters for VAE (concentration of salt, type of solvent and extraction time) and LLE (concentration of salt, extraction time, type and volume of solvent) have been optimised and subsequently applied to the extraction using the real samples. Ten cosmetic products were chosen randomly such as shampoo, body wash, gargle, toner, mouth rinse, lotion, feminine wash, face mask, and scrub. The recoveries for VAE and LLE were 76.7% -103.4% (RSD=0.1-4.0%) and 62.5%-93.9% (RSD=&lt;1%), respectively. Therefore, VAE is the best modern method for determination of propylparaben in cosmetics because it is simpler, faster with high percentage of recovery compared to other techniques.

Estimating Diphenylamine in Gunshot Residues from a New Tool for Identifying both Inorganic and Organic Residues in the Same Sample

A method involving the collection and determination of organic and inorganic gunshot residues on hands using on-line in-tube solid-phase microextraction (IT-SPME) coupled to miniaturized capillary liquid chromatography with diode array detection (CapLC-DAD) and scanning electron microscopy coupled to energy dispersion X-ray (SEM-EDX), respectively, for quantifying both residues was developed. The best extraction efficiency for diphenylamine (DPA) as the main target among organic residues was achieved by using a dry cotton swab followed by vortex-assisted extraction with water, which permits preservation of inorganic residues. Factors such as the nature and length of the IT-SPME extractive phase and volume of the sample processed were investigated and optimized to achieve high sensitivity: 90 cm of TRB-35 (35% diphenyl, 65% polydimethylsiloxane) capillary column and 1.8 mL of the processed sample were selected for the IT-SPME. Satisfactory limit of detection of the method for analysis of DPA deposited on shooters’ hands (0.3 ng) and precision (intra-day relative standard deviation, 9%) were obtained. The utility of the described approach was tested by analyzing several samples of shooters’ hands. Diphenylamine was found in 81% of the samples analyzed. Inorganic gunshot residues analyzed by SEM-EDX were also studied in cotton swab and lift tape kit samplers. Optical microscopy was used to see the inorganic gunshot residues in the cotton swab samplers. The lift tape kits provided lesser sensitivity for DPA than dry cotton swabs—around fourteen times. The possibility of environmental and occupational sources could be eliminated when DPA was found together with inorganic residues. Then, the presence of inorganic and organic residues in a given sample could be used as evidence in judicial proceedings in the forensic field.

A simple vortex-assisted graphene oxide nanosheets dispersive micro-solid phase extraction combined with high-performance liquid chromatography for UV-Vis detection of tramadol in biological samples

ABSTRACTThis study developed a simple, rapid and sensitive method that utilizes vortex-assisted graphene oxide nanosheets dispersive micro-solid phase extraction of tramadol hydrochloride from biological samples. The data obtained from scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy confirmed the characteristics of graphene oxide nanosheets (GONSs). In order to increase the extraction efficiency, a vortex was applied in the extraction process. In this study, parameters affecting the extraction efficiency were identified and discussed. The optimal experimental parameters were as follows: pH, amount of GONSs, type and volume of desorption solvent, vortexing time, and addition of NaCl. Under optimized conditions, this method allowed the determination of tramadol in the range of 5–300 µg l−1 and the limit of detection was 0.16 µg l−1. The intra-day and inter-day precisions obtained were 2.4% and 3.8%, respectively. This method can be used as an analytical technique for the determination of tramadol in biological samples.

Simultaneous Determination of Arsenic and Lead in Vegetable Oil by Atomic Fluorescence Spectrometry after Vortex-Assisted Extraction

ABSTRACTHydride generation atomic fluorescence spectrometry (HG-AFS) is used for the determination of hydride-forming elements due to its high sensitivity, simplicity, and low cost. A new HG-AFS method for the simultaneous determination of arsenic and lead in vegetable oil is reported. Vortex-assisted extraction with dilute nitric acid was used to isolate arsenic and lead from vegetable oil. The conditions influencing the fluorescence signal, including the carrier fluid, oxidizing agent, and reducing agent, were optimized. The interferences of coexisting ions were also evaluated. Under the optimized conditions, the limits of detection were 0.6 and 0.4 µg kg−1 for arsenic and lead. The recoveries were from 84.4 to 105% for both metals in vegetable oil. The optimized method was used for the determination of arsenic and lead in commercial vegetable oil. The analytical results by this approach were in good agreement with values obtained by inductively coupled plasma mass spectrometry with microwave digestion.

Determination of benzo[a]pyrene in camellia oil via vortex-assisted extraction using the UPLC-FLD method.

In this paper, vortex-assisted extraction using the ultraperformance liquid chromatography analysis method was performed to determine benzo[a]pyrene in camellia oil. Optimum results were obtained when 0.5 g of oil sample was used followed by vortex-assisted extraction for 10 min with 25 mL of acetonitrile. Chromatographic separation was performed on an Agilent ZORBAX Eclipse Plus C18 column (2.1mm×100mm, particle size 1.8 μm). The optimum mobile phase comprised 70% acetone and 30% water. The detection limit of benzo[a]pyrene was 0.2 μg/kg. The recoveries were in the range of 81.0-97.0%. The proposed method was simple and fast, and it provided high throughput in the determination of benzo[a]pyrene in an oil matrix sample.

Simultaneous Analysis of Ursolic Acid and Oleanolic Acid in Guava Leaves Using QuEChERS-Based Extraction Followed by High-Performance Liquid Chromatography.

In this paper, a novel method of QuEChERS-based extraction coupled with high-performance liquid chromatography has been developed for the simultaneous determination of ursolic acid (UA) and oleanolic acid (OA) in guava leaves. The QuEChERS-based extraction parameters, including the amount of added salt, vortex-assisted extraction time, and absorbent amount, and the chromatographic conditions were investigated for the analysis of UA and OA in guava leaves. Under the optimized conditions, the method showed good linearity over a range of 1–320 μg mL−1, with correlation coefficients above 0.999. The limits of detection of UA and OA were 0.18 and 0.36 μg mL−1, respectively. The intraday and interday precision were below 1.95 and 2.55%, respectively. The accuracies of the UA and OA determinations ranged from 97.4 to 111.4%. The contents of UA and OA in the guava leaf samples were 2.50 and 0.73 mg g−1, respectively. These results demonstrate that the developed method is applicable to the simultaneous determination of UA and OA in guava leaves.

Fatty acids profiling of avocado seed and pulp using gas chromatography–mass spectrometry combined with multivariate chemometric techniques

In the present study, the profiling of 17 fatty acids (FAs) in avocado seed and pulp was investigated. The fatty acids were extracted with vortex-assisted extraction, methyl esterified and finally preconcentrated by dispersive liquid–liquid microextraction. The preconcentrated fatty acid methyl esters (FAMEs) were analyzed using gas chromatography–mass spectrometry (GC–MS) to obtain qualitative and quantitative information. The GC–MS data were analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method to overcome general chromatographic problems such as overlapped peaks, background interference and peak shifts. The calibration data were prepared using pure analytical information obtained by MCR-ALS. The linear dynamic ranges and regression coefficients (R 2) for FAMEs were in the range of 0.19–65 mg L−1 and 0.990–0.999, respectively. The relative standard deviation (RSD%) for determination of FAs in avocado seed and pulp was 0.17–8.84 and 0.64–17.93, respectively. The main FAs in the avocado pulp were: oleic acid (74.25 g Kg−1), linoleic acid (26.87 g Kg−1), palmitic acid (26.02 g Kg−1), palmitoleic acid (1.22 g Kg−1) and stearic acid (0.05 g Kg−1). And, the main FAs in the avocado seed were: linoleic acid (1.09 g Kg−1), palmitic acid (0.47 g Kg−1), oleic acid (0.33 g Kg−1), linolenic acid (0.12 g Kg−1), and palmitoleic acid (0.04 g Kg−1).

Spectrophotometric determination of low levels arsenic species in beverages after ion-pairing vortex-assisted cloud-point extraction with acridine red

ABSTRACTA new, low-cost, micellar-sensitive and selective spectrophotometric method was developed for the determination of inorganic arsenic (As) species in beverage samples. Vortex-assisted cloud-point extraction (VA-CPE) was used for the efficient pre-concentration of As(V) in the selected samples. The method is based on selective and sensitive ion-pairing of As(V) with acridine red (ARH+) in the presence of pyrogallol and sequential extraction into the micellar phase of Triton X-45 at pH 6.0. Under the optimised conditions, the calibration curve was highly linear in the range of 0.8–280 µg l−1 for As(V). The limits of detection and quantification of the method were 0.25 and 0.83 µg l−1, respectively. The method was successfully applied to the determination of trace As in the pre-treated and digested samples under microwave and ultrasonic power. As(V) and total As levels in the samples were spectrophotometrically determined after pre-concentration with VA-CPE at 494 nm before and after oxidation with acidic KMnO4. The As(III) levels were calculated from the difference between As(V) and total As levels. The accuracy of the method was demonstrated by analysis of two certified reference materials (CRMs) where the measured values for As were statistically within the 95% confidence limit for the certified values.

Determination of Water- and Methanol-Extractable Pentachlorophenol in Soils Using Vortex-assisted Liquid-Liquid Extraction and Gas Chromatography

Abstract An analytical procedure for determination of water- and methanol-extractable pentachlorophenol (PCP) in soils was developed using vortex-assisted liquid-liquid extraction (VALLE) and gas chromatography (GC). Significant extraction parameters such as vortex speed and liquid-liquid volume ratio were optimized for extracting PCP from solution. The recovery of PCP was the highest (97.4%) with good reproducibility and a small relative standard deviation (RSD, 0.5%) when the vortex speed was at 2000 rpm. Meanwhile, when the volume ratio of derivatization solution to n-hexane was at 10:4, the recovery of PCP was 103% with a RSD of 0.7%. The linearity of the calibration curve for PCP determination ranged from 1.25 μg L−1 to 4000 μg L−1, with a correlation coefficient (R2) of 0.9999. The detection limit of PCP in water samples was below 0.2 μg L−1 and the measuring range was relatively wide, and suitable for trace- and micro-analysis of PCP. Compared with traditional extraction methods (liquid-liquid and solid-phase), VALLE consumes less extractant, requires fewer steps, and achieves higher recovery (96.8%) and smaller RSD (3.7%). The reliability of VALLE was verified in four distinct types (paddy, red, black and alluvial) of soil samples spiked with 1 and 10 mg kg−1 PCP. The total recoveries of PCP in the soil samples were in the range of 89.5%–98.9% by water extraction and 88.7%–98.4% by 3 consecutive extractions with methanol in a sequential procedure. The results indicated that VALLE-GC satisfied the requirements for extracting and determining water- and methanol-extractable PCP in soils polluted by PCP at varying levels.

Determination of Trace Elements in Camellia Oil by Vortex-Assisted Extraction Followed by Inductively Coupled Plasma Mass Spectrometry

A simple vortex-assisted liquid–liquid extraction protocol followed by ICP-MS has been developed for the determination of nine elements (Cr, Mn, Fe, Ni, Cu, As, Zn, Cd, and Pb) in camellia oil samples. The key parameters affecting the extraction efficiency (extraction solvent characteristics, extraction time, and solvent/oil ratio) were carefully examined and optimized. Optimum results were obtained when 5 g of oil sample was used followed by vortex-assisted extraction for 20 min with 10 mL of 10 % HNO3 (v/v). Detection limits ranging from 0.03 to 1 μg L−1 and relative standard deviation lower than 6 % were obtained. The accuracy of the method was assessed by spiking experiments and comparison of the results from the extraction procedure with those obtained from microwave-assisted digestion of the samples. The recoveries were in the range of 84.3~102.3 %. No statistical differences, based on t test at a confidence level of 95 %, were detected. The proposed method was found to be simple, fast, and accurate when applied to camellia seed oil samples and has great potential in quantitatively detecting elements in various oils.

Vortex-assisted extraction in tandem with dispersive liquid–liquid microextraction followed by GC-MS for determination of Achillea wilhelmsii essential oil

A simple, fast and efficient combined extraction/preconcentration method composed of vortex-assisted extraction (VAE) and dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for determination of essential oil constituents of the plant Achillea wilhelmsii. Methanol and chloroform were used as the extraction and preconcentration solvents, respectively. The effective parameters of the extraction process were optimized by the one-at-a-time method. The optimal conditions were determined as 25 μL of chloroform, 7.5% (w/v) of salt concentration, and 2 min of extraction time. The linear dynamic range (LDR) for the oil components was within 0.01–100 and 0.1–100 mg L−1 characterized by determination coefficients (R2) between 0.9990 and 0.9998. The limits of detection (LODs) were from 3.0 to 30.0 μg L−1. The relative standard deviations (RSDs, n = 5) were 2.3–4.7%. The enhancement factors (EFs) ranged from 80 to 91. The extraction yield of the essential oil by hydrodistillation was 1.02% (w/w). The main components of the Achillea wilhelmsii essential oil were determined as: borneol (21.23%), cis-chrysanthenyl acetate (20.92%), camphor (9.24%), trans-chrysanthenyl acetate (8.63%) and 1,8-cineole (7.16%). The antimicrobial activity of the essential oil against 10 different species of bacteria with two most commonly used methods of the disc diffusion method (DDM) and the broth dilution method (BDM) was investigated. The essential oil showed inhibitory activity against Escherichia coli, Bacillus cereus, and Staphylococcus aureus with the highest activity for Escherichia coli.