Accelerated Solvent Extraction Method Research Articles

Investigation of the Effects of Energy-Efficient Drying Techniques and Extraction Methods on the Bioactive and Functional Activity of Banana Inflorescence

Plant-derived foods with therapeutic potential have strong connection with both the pharmaceutical and nutraceutical industries. The effectiveness of these therapeutic properties is heavily influenced by the thermal treatment during drying and extraction methods. Traditional convective drying is a very energy incentive and lengthy process. Although some advanced and hybrid drying methods have been developed, these have not been applied in drying of banana inflorescence. In this study, we investigated the effects of freeze-drying (FD) and intermittent microwave convective drying (IMCD), as well as traditional convective oven drying (CD), on the polyphenol profile of banana inflorescence when extracted using the energy-efficient Accelerated Solvent Extraction method (ASE). Our findings revealed that the freeze-dried banana inflorescence powder exhibited the highest extraction of bioactive compounds when using 75% methanol at 100 °C as a solvent. It recovered 2906.3 ± 20.83 mg/100 g of the phenolic compounds and 63.12 ± 0.25% antioxidant activity under the optimal extraction conditions. While IMCD was found to be the second-best drying method in terms of preserving bioactive compounds, its operational time and cost were significantly lower compared to freeze-drying. Furthermore, our study confirmed the presence of medicinal compounds such as gallic acid, protocatechuic acid, caffeic acid, coumaric acid, catechin, ferulic acid, kaempferol, and quercetin in banana inflorescence. The development of innovative functional foods and pharmaceutical ingredients through green extraction methods and optimal drying conditions holds significant potential to save energy in the process, enhance human health, and promote environmental sustainability and circular economy processes. These efforts align with supporting Sustainable Development Goals (SDGs) 3 and 12.

Effect of accelerated extraction and sonication on the antioxidant capacity of wood and bark extracts of wet-hearted silver fir (Abies alba Mill.)

The aim of this study was to compare the antioxidant capacity of hydrophilic extracts of different tissues of wet-hearted silver fir (Abies alba Mill.) logs. Wet heart is a wood defect of silver fir and lowers the value of wood. The exploitation of extractives could increase utilization and financial returns. The bark, sapwood, heartwood and knotwood were investigated by using two green extraction methods: ultrasound assisted extraction (US) and accelerated solvent extraction (ASE), with aqueous ethanol as solvent. Total extractive content (TEC), total polyphenol content (TPC) and antioxidant capacities (FRAP, DPPH, ABTS) from the extracts were determined and compared. The highest contents of total hydrophilic extractives were measured in knotwood (23.07%, ASE) and bark (10.31%, ASE), and the lowest values were determined for sapwood (2.00%, ASE) and heartwood (3.56%, ASE). The ASE method resulted in significantly higher TPC (0.65–10.58%) than the US (0.46–9.19%) method. Nevertheless, the simplicity of instrumentation and costs can make US also a potential candidate for future extraction and utilization. The highest antioxidant capacities were measured in knotwood (FRAP: 159.75 mg AAE/g, ABTS: 316.15 mg TE/g, DPPH: 189.23 mg TE/g) and bark (FRAP: 159.75 mg AAE/g, ABTS: 126.81 mg TE/g, DPPH: 74.52 mg TE/ g) extracts, prepared with ASE, which complements well the existing literature data on silver fir extractives. The knotwood and bark of wet-hearted silver fir is an abundant source of antioxidant polyphenols, whereas sapwood and heartwood are poor in these extractives and potentially unsuitable for the valorization by the extraction of natural antioxidants.

Identifying organic micropollutants' transformation products from the soil dissipation experiment by non-targeted high-resolution mass spectrometry approach: Can we gain more than transformation product identity?

Risk assessment of environmental hazards originating from xenobiotics extensively used worldwide (e.g., pharmaceuticals, bisphenols, or preservatives) requires a combined study of their effects, mobility, dissipation mechanisms, and subsequent transformation product identification and evaluation. We have developed an efficient accelerated solvent extraction method for a broad range of micropollutants of variable physical-chemical properties in soils to enable more accurate hazard characterisation. Micropollutant recoveries from freeze-dried soils were 60–120%, with the exception of atorvastatin, fexofenadine, and telmisartan, which had reduced recoveries (40–66%). The observed matrix effect ranged from −26% to 17% and was corrected by the matrix matching standard for quantitative analysis. The method allows sensitive and reliable determination of a wide range of analytes in soil samples and, consequently, qualitative analysis of transformation products (TP) with variable physicochemical properties. We identified TPs of five compounds (venlafaxine, telmisartan, valsartan, atorvastatin, and sertraline) by applying suspect and non-targeted data analyses. To our knowledge, the transformation product of atorvastatin was reported for the first time. All others were found in soil or other matrices. Valsartan (formed valsartan acid) and atorvastatin (transformed probably by oxidative decarboxylation of beta, delta dihydroxy heptanoic acid chain to propionic acid) were modified to a relatively large extent. All other compounds identified were only hydroxylated (sertraline and telmisartan) or demethylated (venlafaxine). We estimated the stability and presence of the identified TPs based on the constructed time trends and the ratio between TP formation and degradation rates. We demonstrated how valuable a non-targeted approach can be for complex evaluation of the fate and effect of soil pollutants.

Exploring efficient extraction methods: Bioactive compounds and antioxidant properties from New Zealand damson plums

The study determined the best extraction method for phenolic compounds (rutin, catechin, epicatechin, naringenin, neochlorogenic acid, and rosmarinic acid) in the New Zealand damson plums. Accelerated solvent extraction (ASE) using ethanol and water was used to evaluate the solvent efficacy. Further comparisons were made among ASE, ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), and a combined method (E + UAE) using water as the solvent. The findings showed that ASE for 40 min was the most effective method for extracting phenolic compounds (1.76 mg gallic acid equivalent/g) compared to other methods (UAE = 1.17, EAE = 1.3, and E + UAE = 1.45 mg/g). The ASE method also resulted in an extract with a higher antioxidant activity than other methods. The extraction time over 40 min decreased the yield regardless of the solvent used. Therefore, the ASE extraction method for 40 min is recommended as the best method for extraction of phenolic compounds from the New Zealand damson plums.

Analyses ofElaeocarpus sphaericusextract for antioxidant, anti-proliferative and gene repression activities against HIF-1 alpha and VEGF.

The study presents antioxidant, phytochemical, anti-proliferative, and gene repression activities against Hypoxia inducible factor (HIF-1) alpha and Vascular endothelial growth factor (VEGF) ofElaeocarpus sphaericusextract. Total phenolic content (TPC) and total flavonoid content (TFC) were used to measure the extracts' phytochemical activity (TFC). Antioxidant potential of the extracts was measured through DPPH, ABTS, FRAP, and TRP. Methanol extract of the leaves ofE. sphaericushas shown higher amount of the TPC (94.666±4.040 mg/gm GAE) and TFC value (172.33±3.21 mg/gm RE). The antioxidant properties of extracts in the yeast model (Drug Rescue assay) showed promising results. Ascorbic acid, gallic acid, hesperidin, and quercetin were found in the aqueous and methanolic extracts ofE. sphaericusat varying amounts, according to a densiometric chromatogram generated by HPTLC analysis. Methanolextract ofE. sphaericus(10 mg/ml) has shown good antimicrobial potential against all bacterial strains used in the study exceptE. coli.The anticancer activity of the extract in HeLa cell lines ranged from 77.94±1.03% to 66.85±1.95% while it ranged from 52.83±2.57% to 5.44% in Vero cell lines at varying concentration (1000µg/ml-31.2 µg/ml). A promising effect of extract was observed on the expression activity of HIF-1 and VEGF gene through RT-PCR assay.

Antioxidant Activity of Andrographolide from Andrographis paniculataleaf and Its Extraction Optimization by using Accelerated Solvent Extraction

Andrographis paniculata is widely used as a medicinal plant in many countries and andrographolide is the major bioactive compound extracted from A. paniculata leaf. This study purposely to optimize statistical andrographolide extraction using the accelerated solvent extraction (ASE) technique. The Box Behnken design (BBD) was chosen to determine the optimum ASE conditions for the extraction temperature (ºC), cycle number, and extraction time (min) to achieve the highest yield of andrographolide. The optimum ASE conditions were identified as: extraction temperature of 60 ºC, using 3 cycles and 5 min extraction time, with maximum conversion yield as high as 335.2 ± 0.2 mg/g determined by High Performance Liquid Chromatography (HPLC) with the squared correlation coefficients (R2) of 0.97. The findings revealed the ASE method significantly enhanced andrographolide extraction and agreed closely with the predicted value at 337.5 mg/g. Andrographolide was isolated by preparative HPLC technique. A. paniculata leaf extract and extracted andrographolide displayed moderate radical scavenging activity in 2, 2−Diphenyl−1−picrylhydrazyl hydrate (DPPH) assay with IC50 of 0.883 ± 1.597 mg/ml and 0.514 ± 0.285 mg/ml respectively as IC50 for ascorbic acid was 0.048 ± 0.004 mg/ml. A. paniculata extract and andrographolide inhibited the tyrosinase enzyme with IC50 of 0.749 ± 0.293 μg/ml and IC50 of 2.441 ± 2.026 μg/ml indicated stronger tyrosinase inhibition abilities than kojic acid, IC50 of 19.985 ± 0.557 μg/ml. These results suggest that A. paniculata leaf extract and andrographolide have greater potential as sources of biochemical compounds that can be used as skin depigmentation solutions.

Extraction of biologically active compounds from Aronia melanocarpa: Comparison of techniques and multiple response optimization

Abstract The presented paper deals with the selection of most efficient extraction method for obtaining biologically active compounds (mainly antioxidants) from the black chokeberry (Aronia melanocarpa) fruits. Two conventional methods (maceration and Soxhlet extraction) as well as a more recent accelerated solvent extraction (ASE) were employed. The extracts were evaluated by means of their overall yield, antioxidant activity (TEAC assay), total phenolic content (TPC), ascorbic acid (AA), and malic acid (MA) content. Both Soxhlet extraction and ASE led to the highest overall yields (42 %) of the extract; however, in terms of TEAC and TPC, the extracts obtained by ASE were usually superior. The highest TEAC value (227.7 mg TE/g) as well as the highest TPC (67.9 mg GAE/g) were obtained by ASE using 40 % (v/v) ethanol at 140 °C after 30 min. The ASE method was further analyzed using a 23-factorial design where the effect of temperature (40—140 °C), extraction time (5—30 min), and solvent composition (40—96 % ethanol) was investigated. While temperature and solvent composition significantly affected the extract properties, the effect of extraction time was small or even insignificant. The regression model obtained from ANOVA was further used for multiresponse optimization of ASE conditions using the global desirability function as a criterion for overall extract quality.

Optimization of accelerated aqueous ethanol extraction to obtain a polyphenol-rich crude extract from rambutan (Nephelium lappaceum L.) peel as natural antioxidant

An accelerated solvent extraction method was used to recover polyphenol-rich crude extract from rambutan (Nephelium lappaceum L.) peel, a waste product from the canning industry. The influence of extraction parameters including temperature, extraction time and ethanol concentration on extraction yield, total phenolic content, total anthocyanin content, and ABTS antioxidant activity was investigated. A Box-Behnken design and response surface methodology were used to optimize the extraction process. Optimal conditions were obtained at temperature, extraction time, and ethanol concentration of 60 °C, 34 min, and 54 vol%, respectively. These optimum conditions gave 333.01 ± 5.84 mg gallic acid/g, 318.28 ± 5.56 mg cyanidin-3-O-glucoside/g, and 3.05 ± 0.04 mmol Trolox/mg for total phenolic content, total anthocyanins content, and ABTS activity, respectively with extraction yield of 28.68 ± 1.48 wt%. Important active compounds found in the extract were geraniin, ellagic acid, shikimic acid and corilagin. Crude extract concentrations of 50–500 mg/kg retarded linoleic acid oxidation but efficacy was lower than synthetic antioxidants at 200 mg/kg. The current findings indicated that accelerated aqueous ethanol extraction was an effective method for the recovery of a crude extract rich in polyphenols from rambutan peel with the potential to be used as a natural antioxidant.

The Anti-Inflammatory Properties of Chaga Extracts Obtained by Different Extraction Methods against LPS-Induced RAW 264.7.

Chaga, a sclerotia formed by the Inonotus obliquus fungus, has been widely recognized for a number of medicinal properties. Although numerous scientific investigations have been published describing various biological activities of chaga from different geographical locations, little work has focused on chaga harvested in the USA or extraction techniques to maximize anti-inflammatory properties. The aim of this study was to investigate the anti-inflammatory properties of chaga collected in Maine (USA) extracted using traditional aqueous (hot water steeping) methods against lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Chaga extracts obtained from both conventional (ethanol/water) extraction methods and an accelerated solvent extraction method (ASE) at optimized conditions were compared to aqueous extracts (tea) obtained from chaga in the powder form (P) and powder form in tea bags (B) based on their effect on both nitric oxide (NO) production and pro-inflammatory cytokine expression, in particular, the expression of TNF-α, interleukin-6 (IL-6), and interleukin-β (IL-1β). Phenolic acid extracts from chaga and individual phenolic acid standards were also investigated for their effect on the same parameters. Results indicated that various chaga extracts have significant anti-inflammatory activity on LPS-stimulated RAW 264.7 cells. The inhibitory effect was through a decrease in the production of NO and the downregulation of TNF-α, IL-6, and IL-1β in RAW 264.7 macrophages. ASE1 (novel, optimized ethanol/water extraction) and P6 (six-minute steeping of powder in 100 °C water) extracts showed the highest inhibitory activity on NO production and on the expression of the inflammatory cytokines, compared to extracts obtained by conventional extraction methods.

Crystal film accelerated solvent microextraction (CF-ASME) for determination of flavonoids in natural products combined with high performance liquid chromatography

A simple and efficient crystal film accelerated solvent microextraction (CF-ASME) technique was developed. In this study, the polyethylene pipe (PEP) with excellent comprehensive performance was used as the carrier of the extraction solvent, on which the crystal film was cured to improve its extraction capacity. The cured PEP was directly immersed in the sample phase solution to enrich the flavonoids (myricetin, quercetin, isorhamnetin, chrysin and kaempferide) in natural products. In addition, the extraction mechanism of the technique was elucidated. The important extraction variables were optimized including extraction solvent, the amount of NaCl required for crystal film preparation, salt concentration and pH of sample phase, stirring rate, extraction time, and volume of sample phase. Under the optimal conditions, the flavonoids were effectively enriched with the enrichment factors of 39.9–146.9 and they obtained good linearity with correlation coefficients higher than 0.99. The limits of detection were ranged between 0.5 and 30 ng/mL. Satisfactory accuracies (recoveries 89.4–104.8%) and precisions (relative standard deviations 5.8–11.2%) were also obtained. The proposed method was successfully applied for extraction and determination of flavonoids in natural products. Compared with the general accelerated solvent extraction methods, CF-ASME is simple to operate, green, high enrichment efficiency, which has a good application prospect.

Optimizing accelerated solvent extraction combined with liquid chromatography-Orbitrap mass spectrometry for efficient lipid profile characterization of mozzarella cheese

In this study, a novel Accelerated Solvent Extraction (ASE) procedure combined with UHPLC-Q-Orbitrap-MS was developed for detailed untargeted lipid profile of mozzarella cheese. Response Surface Methodology and Pareto front, using a Central Composite Design (CCD), were employed to define the optimised combination of extraction temperature, number of extraction cycles and mix of solvents. LipidSearch™ software was used for a reliable and accurate lipid identification. A total of 13 subclasses, including ceramides, diacylglycerols, triacylglycerols, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, sphingomyelins, bismethyl phosphatidic acids, cholesterol ester, zymosterol ester, hexosyl ceramides were measured. The elaboration of the CCD showed that the solvents ratio was the main factor affecting the extraction efficiency. The optimised ASE method, together with the Folch extraction, synergistically contributed to a complete characterization of lipid profile of mozzarella cheese, confirming ASE technique, associated with high resolution mass spectrometry detection, as an efficient tool for Lipidomics in food science.

Optimization of the Efficient Extraction of Organic Components in Atmospheric Particulate Matter by Accelerated Solvent Extraction Technique and Its Application

Organic components in atmospheric fine particulate matter have attracted much attention and several scientific studies have been performed, although most of the sample extraction methods are time consuming and laborious. Accelerated solvent extraction (ASE) is a new sample extraction method offering number of advantages, such as low extraction cost, reduced solvent and time consumption, and simplified extraction protocols. In order to optimize ASE methods to determine the concentrations of organic compounds in atmospheric fine particulate matter, different parameters were set out for the experiment, and the optimal method was selected according to the recoveries of the standard (i.e., n−alkanes and polycyclic aromatic hydrocarbons (PAHs)). This study also involves a comparison of the optimal method with the traditional method of ultrasonic extraction (USE). In addition, the optimized method was applied to measure the mass concentrations of organic compounds (n−alkanes and PAHs) in fine particulate matter samples collected in Beijing. The findings showed that the average recovery of target compounds using ASE was 96%, with the majority of compounds falling within the confidence levels, and the ASE recoveries and precision were consistent with the USE method tested. Furthermore, ASE combines the advantages of high extraction efficiency, automation, and reduced solvent use. In conclusion, the optimal ASE methods can be used to extract organic components in atmospheric particulate matter and serve as a point of reference for the development of analytical methodologies for assessing organic compounds in atmospheric particulate matter in China.

Optimization of accelerated solvent extraction of paprika oleoresin and its effect on capsaicinoid and carotenoid composition

Accelerated solvent extraction (ASE) is an automatic extraction technology that performs at elevated temperature and pressure to achieve efficient extraction of compounds from solid or semisolid samples in a very short time. In this study, the response surface method (RSM) was used to establish an efficient ASE method for rapid extraction of high-quality paprika (Capsicum) oleoresin with American Spice Trade Association (ASTA) color value as the response variable. The ASTA color values and pungency levels of paprika oleoresin obtained by ASE, maceration extraction (ME) and ultrasound-assisted extraction (UAE) were further compared. The optimal conditions for ASE procedure are a static time of 28 min, an extraction temperature of 78 °C, and 2 cycles. Under these optimal conditions, the ASTA color value of extracted paprika oleoresin reached 847 and the scoville heat unit (SHU) reached 57,200 ± 362. These values were significantly higher than those obtained by ME (ASTA color value: 607, SHU: 42,800 ± 144) or UAE (ASTA color value: 750, SHU: 50,500 ± 1690). These results were also reflected by total carotenoid and capsaicinoid content. There was little difference in carotenoid distribution in ASE, ME and UAE samples. In addition, ASE did not promote additional trans/cis transformation of carotenoids.

New Residue Analysis Method for Four Task-Specific Ionic Liquids in Water, Soil and Plants.

With the extensive application of task-specific ionic liquids (TSILs), their environmental impact has attracted increasing attention. However, no studies involving residue analyses of TSILs have been reported in the literature thus far. In the present study, residues of four TSILs ([C2NH2MIm]BF4, [HOEMIm]BF4, [HOEMIm]NO3, [MOEMIm]BF4) were analyzed by high-performance liquid chromatography-tandem mass spectrometry. The limit of detection of instrument was approximately 10-15g. Residual TSILs were extracted from soil and plant samples by the accelerated solvent extraction method. In water, soil and plants, the coefficient of variation was 0.38%-4.43%, and the method detection limits of the four TSILs were lower than 1.40ngg-1. These results meet the standards of residue analysis. The present study can provide an analysis method for studying TSIL residues and toxicity in the environment.

Selective and Sensitive Quantification of Acetochlor and S-Metolachlor in Maize and Soybean Plant Samples by Gas Chromatography-Tandem Mass Spectrometry

Herbicide residue analysis has gained importance worldwide, mainly for food quality control to minimize potentially adverse impacts on human health. A Gas chromatography-tandem mass spectrometry (GC-MS) method for quantitative analysis of acetochlor and s-metolachlor in maize and soybean straw has been developed, validated and applied to analyze the residues of anilide herbicides. Straw material was dried, homogenized and extracted with a mixture of n-hexane and acetone by an accelerated solvent extraction method. Chromatographic separation of the target analytes was performed on an Agilent 7832 GC equipped with a mass spectrometer detector, a split-splitless injector and an HP-5 MS (5% phenylmethyl siloxane) capillary column (30 m × 0.25 mm × 0.25 µm). Under these parameters, the limit of detection (LOD) values were 0.2 ng g−1 for acetochlor and 0.07 ng g−1 for s-metolachlor, with average recoveries between 86% and 119.7%. The method was validated for acetochlor and s-metolachlor in maize and soybean straw at 0.5 and 0.01 mg kg −1. Furthermore, the final residues of the two herbicides in maize and soybean straw were below the maximum residue limit (MRL) at harvest time. The proposed method is suitable for routine analysis.

New approaches to reduce sample processing times for the determination of polycyclic aromatic compounds in environmental samples

This study validates two approaches to streamlining the processing of sediment and biota for a suite of polycyclic aromatic compounds (PACs) with a wide range of chemical properties, including polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs (APAHs), and a new class of environmental contaminants, halogenated PAHs (HPAHs). One method is based on one-step in situ extraction/cleanup using accelerated solvent extraction (ASE) in which a mixture of copper, deactivated alumina and silica gel were added directly to the ASE cell along with sample; the second technique is based on dispersive solid phase extraction (dSPE) using alumina/silica for cleanup of biota samples to augment conventional ASE extraction combined with gel permeation chromatography. Validation protocols were performed in accordance with the ISO/IEC 17025 guidelines, whereby method performance characteristics, i.e., accuracy, precision, linearity, limits of detection and ruggedness, were evaluated. Accuracies generally ranged from 70 to 120% for the in situ ASE method and 70–100% for the dSPE technique. Limits of detection/quantitation for the 45 target analytes for in situ ASE and dSPE methods were determined to be < 2.5/8 pg μL−1, and < 20/60 pg μL−1, respectively. Intra- and inter-day repeatability for both methods were < 25% except for 1 APAH which had an inter-day precision of 35% using the dSPE method. Neither method was affected by any of the purposeful changes attempted which implies that both methods are robust. Results of our validation studies showed excellent data quality for both methods in addition to achieving a reduction in sample processing times.

Adapting the Accelerated Solvent Extraction Method for Resin and Rubber Determination in Guayule Using the BÜCHI Speed Extractor.

Guayule (Parthenium argentatum Gray) is a promising alternative source to Hevea brasiliensis for the production of natural rubber, which can reach levels of 8–9% under industrialized farming conditions. The most common method for determining rubber concentration is by accelerated solvent extraction (ASE), a technique developed by the Dionex Corporation and almost exclusively performed with the Dionex ASE-200 or 350 systems. Herein, it is sought to apply and adapt the most common methods used in the literature for the Dionex system to another extraction platform, the BÜCHI Speed Extractor E-914. Results showed that using a sand sandwich method to confine the sample in the center and exploiting a larger cell volume (80 mL) for extraction prevents the occurrence of overpressure and problems with clogging. Under optimized conditions, the coefficient of variation was <15% for both resin quantification for samples containing 5.0–15.8% of resin and for rubber quantification for samples with 1.7–10.3% rubber content. The extraction time for resin (2 cycles of 5 min each) was smaller than for rubber (2 cycles of 20 min each). It would be interesting to carry out interlaboratory comparisons to standardize the method at an international level.

Research progress on analytical methods for the determination of hexachlorobutadiene

六氯丁二烯是一种持久性有机污染物,于2015年和2017年分别被列入《斯德哥尔摩公约》附件A和附件C的受控污染物名单中。六氯丁二烯的来源、环境赋存和影响等研究对控制该新增受控持久性有机污染物污染具有重要意义,而灵敏可靠的六氯丁二烯分析方法是开展相关研究的前提和基础。近年来已有不少学者将六氯丁二烯作为分析目标物之一进行了检测或方法学研究。基于这些研究成果,该文综述了六氯丁二烯分析方法的研究进展,其中重点介绍了空气、水体、土壤、污泥、生物组织等多种介质中六氯丁二烯的样品前处理方法,并比较了各方法的优缺点,以期为该领域的进一步研究提供参考。空气中六氯丁二烯主要由泵抽气通过吸附管而采集,再经热脱附后进行仪器分析,检出限在ng/m3水平。也有研究应用聚氨酯泡沫被动采样器和吸附剂填充聚氨酯泡沫被动采样器采集大气中六氯丁二烯及其他污染物。基于吸附剂填充聚氨酯泡沫被动采样器的分析方法灵敏度较高,其对六氯丁二烯的检出限低至0.03 pg/m3。然而目前被动采样体积仅根据六氯丁二烯的log KOA系数估算,未来仍需进一步实验校正。水体样品前处理通常也较简单,通过吹扫捕集、液-液萃取或固相萃取目标物后进行仪器分析。固相萃取法能够同步实现目标物的提取、净化和浓缩,在水样中六氯丁二烯分析方面具有明显优势。固相萃取柱类型以及干燥步骤中柱中残留水分去除率均会影响六氯丁二烯的回收率。灰尘、土壤、沉积物、污泥和生物组织等固体介质样品基质最为复杂,需联合多种方法进行前处理。固体样品中六氯丁二烯提取方法包括索氏提取,加速溶剂萃取和超声萃取,其中超声萃取法应用最为广泛。固体基质净化方面主要采用层析柱色谱法,多根净化柱联用或多层复合柱能够提升净化效果。仪器分析方面,六氯丁二烯主要采用气相色谱和质谱联用检测,高性能质谱检测器如串联质谱能够大大提高六氯丁二烯的检测灵敏度,具有较大的应用潜力。

Automated accelerated solvent extraction method for total lipid analysis of microalgae

For algae-based biofuel researches, it is usually necessary to extract and quantitatively measure total lipids. The most popular total lipid determination methods for tissues are solvent-based methods with either manual or Soxhlet extraction. Although some investigators have modified these traditional methods, the modifications have rarely been specified in detail, nor has their effectiveness been critically evaluated on microalgae biomass. As a result, there are often significant differences in the analyses of total lipid contents among investigators and laboratories. To assess the effectiveness of different total lipid extraction protocols for microalgae, several conventional lipid extraction methods were systematically compared with an accelerated solvent extraction (ASE) method. Optimal conditions for the ASE method were determined to be three cycles of 3 min at 125 °C using a 5 ml extraction cell containing 20 to 150 mg of dry algal biomass. Critical comparisons and assessments of these total lipid extraction methods from microalgae were performed for both total lipid extraction efficiency and extracted lipid quality (lipid decomposition and oxidation). Results obtained from five algal species indicated that hot Soxhlet extraction and ASE were comparable in total lipid extraction efficiencies, which were higher than the efficiencies obtained from conventional manual extraction methods. However, lipid oxidation resulting from different extraction methods indicated that continuous heating with a hot Soxhlet extraction method could lead to lipid oxidation. Considering the efficiency and quality of the extracted lipids, extraction time, extraction steps and consumed solvent volumes, ASE is a very promising method for total lipid extraction and analysis of lipids from microalgal biomass.

Quantitative Analysis of Spectinomycin and Lincomycin in Poultry Eggs by Accelerated Solvent Extraction Coupled with Gas Chromatography Tandem Mass Spectrometry.

A method based on accelerated solvent extraction (ASE) coupled with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed for the quantitative analysis of spectinomycin and lincomycin in poultry egg (whole egg, albumen and yolk) samples. In this work, the samples were extracted and purified using an ASE350 instrument and solid-phase extraction (SPE) cartridges, and the parameters of the ASE method were experimentally optimized. The appropriate SPE cartridges were selected, and the conditions for the derivatization reaction were optimized. After derivatization, the poultry egg (whole egg, albumen and yolk) samples were analyzed by GC-MS/MS. This study used blank poultry egg (whole egg, albumen and yolk) samples to evaluate the specificity, sensitivity, linearity, recovery and precision of the method. The linearity (5.6–2000 μg/kg for spectinomycin and 5.9–200 μg/kg for lincomycin), correlation coefficient (≥0.9991), recovery (80.0%–95.7%), precision (relative standard deviations, 1.0%–3.4%), limit of detection (2.3–4.3 μg/kg) and limit of quantification (5.6–9.5 μg/kg) of the method met the requirements for EU parameter verification. Compared with traditional liquid–liquid extraction methods, the proposed method is fast and consumes less reagents, and 24 samples can be processed at a time. Finally, the feasibility of the method was evaluated by testing real samples, and spectinomycin and lincomycin residues in poultry eggs were successfully detected.