Assisted Solvent Research Articles

Quality by design in the optimization of the ultrasonic assisted solvent extraction for the GC-MS determination of plasticizers in sediments and shells

Phthalate esters (PAEs) are the most widely used plasticizers worldwide and are considered as ubiquitous environmental contaminants. Due to both their ubiquity and potential health and environmental risks, their determination is a matter of worldwide concern. In the present study, an efficient method based on ultrasonic-assisted solvent extraction followed by gas chromatography-mass spectrometry is proposed for the simultaneous determination of PAEs and di(2-ethylhexyl) adipate in estuarine sediments and shells. Method optimization was successfully carried out according to Quality by Design principles. Shaking time, ultrasonic time, extractant volume, and solvent type were selected as Critical Method Parameters. Validation proved method reliability for the determination of the investigated analytes, achieving detection limits in the 0.1–0.7 ng g–1 and 0.1–0.5 ng g–1 range for sediments and shells, respectively. A good precision was obtained with RSD < 20% and trueness (recovery) in the 73(±7)–120(±10)% and 70(±10)–111(±3)% range, for sediments and shells, respectively. Finally, the method was applied to analyze sediment samples and mollusc shells, collected from the Curonian Lagoon (Southeast Baltic Sea). Di(2-ethylhexyl) phthalate was present in all the analyzed samples, thus pointing out its ubiquity in estuarine environment. PAEs were also found in shell debris or living mussels, highlighting them as a hotspot of organic contaminants, especially in transitional environments, where accumulation of organic rich deposits is limited.

Exposure scenario and risk assessment of infants and newborns to bisphenols and their derivatives from diapers

Newborns and infants are more sensitive to harmful compounds such as bisphenols and their derivatives because of their not fully developed detoxification mechanism. Exposure to these substances can lead to developmental problems and health consequences in adulthood. Since disposable baby diapers are used from the first days of life and remain in contact with the baby skin, it seems important to monitor the levels of endocrine disrupting chemicals (EDCs) in such products. Ultrasound assisted solvent microextraction of porous membrane-packed solid sample (UASE-PMSS) was used in sample preparation. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used at determination step. Bisphenol A was quantified with the highest frequency at 81 % of samples tested, ranging from 5.0 to 520 ng/g. BADGE·2HCl was also quantified in high concentrations (from 6.8 to 530 ng/g), but was found in only 15 % of the tested samples. The daily exposure dose (DED) of bisphenols was calculated. In addition health risk assessment was conducted using previous (4 µg/kg BW) and actual (0.2 ng/kg BW) values of tolerable daily intake (TDI) of bisphenol A recommended by European Food Safety Authority (EFSA).

An automated accelerated salting-out assisted solvent extraction (A-ASASE) of stilbenoids from Vitis vinifera L. branches: False proof or a proof of concept?

An automated accelerated salting-out assisted solvent extraction (A-ASASE) was developed. This approach made full use of the advantages of both the accelerated solvent extraction (ASE) technique and salting-out assisted liquid-liquid extraction (SALLE), without any modifications at the level of the ASE machine. The A-ASASE combined an automated extraction at high temperature/pressure and an enrichment step using eco-friendly solvents (e.g., water and ethanol) in a fully integrated and simple way that required only low volumes of solvents. The A-ASASE was successfully applied to extract three stilbenoids, namely E-resveratrol, E-ε-viniferin and E-vitisin B, present in grapevine (Vitis vinifera L.) by-products as a proof-of-concept compound. First, factors affecting the yield of stelbenoids by SALLE were investigated by means of a design of experiment model (DOE). The SALLE was then incorporated into ASE. Various ASE operational parameters such as temperature and number of cycles were also investigated. The highest yield was obtained using a mixture of ethanol-water, 70:30 (v/v) at 60 °C, using three extraction cycles and with 5 min of contact each. The highest yields of stilbenoids were 5.87 ± 0.28 g kg−1 dry weight, 3.27 ± 0.72 g kg−1 dry weight and 1.81 ± 0.2 g kg−1 dry weight for resveratrol, E-ϵ-viniferin and vitisin B, respectively. The A-ASASE was then successfully applied to extract the same stilbenoids from the roots of Vitis vinifera L. These results highlight the applicability of A-ASASE methodology to the extraction and enrichment of the extract in compounds of medium-high polarity in an easy and fully automated way.

Milk Thistle Oil Extracted by Enzyme-Mediated Assisted Solvent Extraction Compared with n-Hexane and Cold-Pressed Extraction.

Silymarin and milk thistle oil have unique biological benefits; however, applying silymarin to milk thistle oil remains a challenge. In this research, the content of silymarin in milk thistle oil conditions using enzyme-mediated solvent extraction was investigated and optimized by response surface methodology. The optimal extraction conditions using enzyme-mediated solvent extraction were as follows: the enzyme-added content was 3.06 mg/mL, the enzymatic hydrolysis temperature was 55.09 °C, and the enzymatic hydrolysis time was 66.28 min. Oil extracted by the enzyme-mediated assisted solvent was further compared with those extracted with n-hexane and cold pressing. Results indicated that the oil extraction using the enzyme-mediated assisted solvent had a lower acid value (2.20 ± 0.01 mg/g) and the highest α-tocopherol content (0.62 ± 0.00 mg/g), total phenols (7.67 ± 0.01 mg/g), and flavonoids (1.06 ± 0.13 mg/g). Furthermore, the antioxidant capacity of milk thistle oils was further investigated. The results showed that the enzyme-mediated assisted solvent-extracted oil had the strongest antioxidant capacity with lower lipid oxide content. Therefore, enzyme-mediated solvent extraction is an excellent method for extracting milk thistle oil.

Comparison of microwave, ultrasound and ultrasound-microwave assisted solvent extraction methods on phenolic profile and antioxidant activity of extracts from jackfruit (Artocarpus heterophyllus Lam.) pulp

This study aimed to investigate the impact of different solvents (water, 60% methanol, 60% ethanol and 60% acetone) and methods (conventional solvent extraction, ultrasound-assisted extraction, microwave-assisted extraction and ultrasound-microwave assisted extraction) on the phenolic profile and antioxidant activity of jackfruit (Artocarpus heterophyllus Lam.) pulp. The Folin-Ciocalteu assay was used to determine the total phenolic content (TPC), and antioxidant activity was measured by DPPH and ABTS assays. The phenolic profiles in different extracts were identified using the UPLC-ESI-Q-TOF-MS/MS technique. The results showed that significant differences (p < 0.05) in TPC were found among different extraction methods, the microwave-assisted extraction with 60% ethanol had the highest TPC (2.40 mg GAE/g) compared with the extracts obtained from other methods. Meanwhile, the highest DPPH radical and ABTS radical cation was found in the 60% ethanol-MAE extracts. Correlation analysis further showed a significant positive correlation between TPC and antioxidant activity (R2 > 0.8, p < 0.001). Seventy-eight phenolic compounds were identified by UPLC-ESI-Q-TOF-MS/MS analysis. The most abundant phenolic compounds in jackfruit pulp were identified in negative mode, with 60% ethanol-MAE being the most effective. The quantity of phenolic compounds extracted varied with different extraction methods indicated that the extraction methods had effects on the phytochemical characteristics.

Antimicrobial bionanocomposites of poly(lactic acid)/ZnO deposited halloysite nanotubes for potential food packaging applications

In this study, nanocomposites of polylactic acid (PLA) with ZnO deposited halloysite nanotubes (HNT) (ZnO@HNT) were synthesized by using ultrasound assisted solvent casting method. The synthesized PLA/ZnO@HNT films were characterized for physical, thermal, mechanical, UV-shielding, barrier properties and antimicrobial activity for food packaging applications. The nanocomposite film PZH2 (consisting 2 wt% ZnO@HNT) showed the best properties with percentage increments over PLA as: surface hydrophobicity (16.5%), water vapor barrier (51.1%), flexibility (79.3%), tensile strength (38.9%), elastic modulus (507.1%), UV barrier property (95.3%), antimicrobial activity (R> 99%). Moreover, a packaging test was performed on cut apples for 6 days storage period to evaluate the potential efficacy of nanocomposite films for food packaging applications. The PZH2 films showed considerably improved results as follows: weight loss = 4.17%; total soluble solids = 10.9°Brix; firmness = 2.4 N; and pH = 4.0. The results have demonstrated efficiency of PLA/ZnO@HNT nanocomposite films as potential food packaging material. • Synthesis of PLA/ZnO@HNT composite films using ultrasound-assisted solvent casting • ZnO@HNT improves mechanical, UV-shielding, barrier properties of PLA films • Excellent antimicrobial properties of PLA/ZnO@HNT films for food packaging • Practical packaging test performed on cut apples stored at room temperature for 6 days • Best properties of PZH2 films: weight loss = 4.17%; TSS = 10.9°Brix; firmness = 2.4 N

Ultrasound–assisted solvent extraction combined with magnetic ionic liquid based-dispersive liquid–liquid microextraction for the extraction of mycotoxins from tea samples

In this work, for the first time, a combination of ultrasound–assisted mixed solvent extraction method with magnetic ionic liquid-based effervescent tablet–assisted dispersive liquid–liquid microextraction has been employed as an efficient method for the extraction of aflatoxins B1, B2, G1, and G2 and ochratoxin A from tea samples. In the extraction process, first the analytes were effectively extracted into a mixture of the solvents optimized by simplex centroid design with the aid of sonication process. Then, the extracted phase was used in the microextraction step to preconcentrate the analytes for obtaining high enrichment factors and low detection limits. Effervescent tablet eliminated the use of disperser solvent. Also magnetic ionic liquids usage as the extraction solvent directed the method towards a green approach. Various parameters that can affect the efficiency of the introduced method were evaluated and under the best experimental situations, satisfactory data including acceptable extraction recoveries (76–88%) and enrichment factors (304−352), low limits of detection (0.15–0.28 ng g–1) and quantification (0.49–0.92 ng g–1), and good repeatability (relative standard deviations equal to or less than 3.1% and 3.5% for intra– and inter-day precisions, respectively) were obtained. Lastly, the proposed method was utilized for the determination of the studied mycotoxins in different tea samples sold in Tabriz city (Iran).

A Simple and Convenient Synthesis of 2, 3-dihydroquinazolin-4(1H)-one Derivatives using MgFe2O4@SiO2-SO3H Catalyst

In the present study, use of MgFe2O4@SiO2-SO3H as an efficient, green, magnetically recoverable & recyclable catalyst for micro-wave assisted solvent free synthesis of 2,3-dihydroquinazolin-4(1H)-ones reaction pathway is presented. The superiorities of this method are higher conversion rate, shorter reaction time, easy isolation of product and reusability of catalyst without remarkable loss of activity. The synthesized 2,3-dihydroquinazolin-4(1H)-ones derivatives were assessed for their antimicrobial and antifungal activity; where, the most of these compounds exhibit potent antibacterial and antifungal activities against various bacteria and fungi.

Rapid extraction of lipid from wet microalgae biomass by a novel buoyant beads and ultrasound assisted solvent extraction method

Microalgae biomass is considered as a sustainable source of biofuels and co-products because of its rapid growth and high lipid yield. However, some challenging steps need to be solved such as biomass harvesting, lipid extraction and transesterification in industrial processing. In this study, a novel method using buoyant beads and ultrasound assisted solvent extraction was developed for efficient lipid extraction from microalgae. The central composite design was used to statistically analyze and evaluate the effects of exposure time, hexane: isopropanol ratio, solid concentration and transducer power on lipid yield. The optimum lipid yield of 18.75 wt% was obtained at exposure time of 13.05 min, hexane: isopropanol ratio of 4.04 v/v, solid concentration of 1.24 w/v% and transducer power of 38%. Compared with ultrasound-assisted solvent extraction method, the disruption efficiency was higher and the particle size was smaller with this novel method. Additionally, the content of polyunsaturated fatty acids was lower and degree of saturated fatty acids was higher compared to the biodiesel produced by modified Bligh & Dyer method. Thus, this work demonstrates that the use of buoyant beads and ultrasound assisted solvent extraction is an efficient method to produce fatty acid methyl ester and raw biodiesel.

Development and validation of a multi-pollutant method for the analysis of polycyclic aromatic hydrocarbons, synthetic musk compounds and plasticizers in atmospheric particulate matter (PM2.5)

Exposure to atmospheric particulate matter (PM) associated pollutants is a global concern due to the risk posed in human health after inhalation. In this study, a simple and sensitive multi-residue method is developed for the analysis of 50 organic pollutants, comprising 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 12 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols in PM2.5 samples. The method consists of three cycles of ultrasonic assisted solvent extraction and vortex (UASE + vortex), followed by a vortex-assisted dispersive solid phase extraction (d-SPE) clean-up and a final determination step by using programmed temperature vaporization-gas chromatography-tandem mass spectrometry (PTV-GC-MS/MS). Experimental conditions concerning clean-up adsorbents (alumina, silica gel and Florisil®) and filters (glass fibre, PTFE and nylon), as well as PTV-GC-MS/MS conditions were studied. In addition, the use of SRM (selected reaction monitoring) mode in MS-MS, as well as matrix-matched calibration together with labelled subrogate standards, resulted in successfully validation results for most of the compounds due to the high sensitivity, minimization of matrix effects and recovering losses compensation. The proposed method was validated in terms of linearity, limits of detection and quantification (LODs and LOQs), analytical recoveries by analysing a spiked composite sample (PM2.5) at three spiking levels and intra-day and inter-day precision. Moreover, an urban particulate matter standard reference material (SRM 1648a) was analysed to assess PAHs determination accuracy. Furthermore, applicability of the method was proved by analysing 12 PM2.5 samples from an industrial area. Among all studied pollutants, bisphenol A (BPA) was the most predominant with an average concentration of 5000 pg m−3, followed by bis(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthtalate (DiBP) with 1990 pg m−3 and 632 pg m-3, respectively. Concerning OPFRs, average concentrations between 345 – 253 pg m−3 were found for triphenyl phosphine oxide (TPPO), tris(chloropropyl) phosphate (TCPP), tri-iso-butyl phosphate (TiBP) and tris(2-butoxyethyl) phosphate (TBOEP). Finally, the highest PAHs levels were found for 5-6 ring-number PAHs (Σ5-6 rings PAHs) with an average concentration of 2680 pg m−3, while only 2 SMCs were quantitated accounting for 17.5 pg m−3 by average.

Anthocyanins from purple passion fruit (Passiflora edulia Sims) rind-An innovative source for nonbleachable pigment production.

Passion fruit rind is a waste product from the beverage industry that is rich in anthocyanins that can be potentially applied as a natural colorant. However, the inherent instability of anthocyanins causes rapid discoloration. In this study, the cyanidin-3-glucoside (C-3-G) in passion fruit rind was extracted using 50% ethanol and converted into nonbleachable pigments by reaction with Oolong tea extracts and acetaldehyde. Reactions over 70 days formed high concentrations of stable nonbleachable pigments (3.07-6.68 absorbance unit [A.U.], in total) such as pyranoanthocyanins, as well as oligomeric and polymeric pigments with ethyl-linked bridges. In C-3-G and acetaldehyde reaction, positive relations were found among acetaldehyde concentration, color density, and nonbleachable pigment concentrations. As for reactions with C-3-G and Oolong tea extract combined with acetaldehyde, greater color density and greater concentrations of nonbleachable pigments (10.80-12.34, 4.25-4.40 A.U., respectively) were formed compared with acetaldehyde alone. In addition, the antioxidant capabilities of the extracts were enhanced after reaction with Oolong tea extracts. The results of this study show a useful method to enhance the stability of anthocyanins from passion fruit rind and also provide greater economic value to this waste product. PRACTICAL APPLICATION: Ripened passion fruits contain a high concentration of anthocyanins in their rind. These anthocyanins can be optimally extracted by ultrasonic assisted solvent extraction to provide stable pigments by inducing acetaldehyde (a volatile compound often found in foods and beverages) into the anthocyanins. These stable pigments have a greater reddish hue in solution than the anthocyanin extracted from the rind and are more stable over a greater pH range. In addition, these stable pigments can be potentially used as colorant throughout the food and cosmetic industry to provide high economical values.

Salting-out assisted solvent extraction of L (+) lactic acid obtained after fermentation of sugarcane bagasse hydrolysate

Lactic acid is among the twelve platform chemicals produced from inexpensive and renewable feedstocks such as lignocellulosic biomass. The present study illustrates salting-out assisted solvent extraction of L (+) lactic acid, derived from sugarcane bagasse hydrolysate. Screening studies with various extractants and diluents revealed that a combination of tri-n-butyl phosphate and ethyl acetate yielded the best results and extracted 59.63 ± 1.28% lactic acid from the dilute fermentation broth adjusted to a pH of 1.6 ± 0.2. Various inorganic salts were screened to enhance extraction efficiency further. The addition of 60% (w/v) ammonium sulfate improved the lactic acid extraction by 36.17%. This salt concentration successfully extracted 85.95 ± 0.44% lactic acid to the organic phase under optimized conditions from the fermentation broth at a pH of ~ 2.5 containing 40–100 g L−1 lactic acid. Recovery of > 80% salt is also shown using chilled acetone, which upon reuse showed a nominal decline of 3.3% during extraction. Thus an eco-friendly approach using a green solvent like ethyl acetate with mild operating conditions is demonstrated in the present study.

Enhancing the extraction of pumpkin seed (Cucurbita pepo L) for increasing oil yield and its phytosterol content

Pumpkin seeds (Cucurbita pepo) were harvested in 2018 containing 41.23±1.23% oil; 33.18±1.61% protein; and 1575.97 ±67.79 mg phytosterol in 100g seeds (dried weight). Solvent (hexane) extraction (SE), Ultrasound assisted solvent (hexane) extraction (UAE), Enzyme Alcalase assisted extraction (EAE) and Enzyme Alcalase_Ultrasound assisted extraction (E_UAE) were studied. The oil’s yields and phytosterol in oil obtained were 90.07±0.17% and 1657.6±82.9 mg/100ml oil; 95.46±0.06% and 2017.5±100.1 mg/100ml oil; 89.65±0.11% and 1992.7±99.5 mg/100ml oil; 91.87± 0.03% and 2327.7 ±110.4 mg/100ml oil, respectively. The highest oil yield of 95.56% was obtained when UAE method was applied, while it was found that the highest phytosterol content of 881.7 mg/100g seeds can be obtained in the case of using E_UAE.

Optimization and technoeconomic analysis of biooil extraction from Calophyllum inophyllum L. seeds by ultrasonic assisted solvent oil extraction

In the present investigation, the bio-oil extraction from Calophyllum inophyllum seeds using an ultrasonic-assisted heterogeneous solvent technique has been carried out in order to avoid diminishing the oil property and quality by high temperature. The application of different combinations of solvent extraction has been examined using Diethyl ether:Ethanol, Chloroform:Methanol, and Isopropanol: Methanol. The results reveals that the equal ratio of Diethyl ether:Ethanol in assistance with ultrasonic waves yields maximum oil extraction. The other optimized process conditions determined by central composite design was found to be the seed kernel to the solvent ratio of 1:15 (w:v); time 45 min; temperature 36 °C and ultrasonication power of 54 % yields maximum bio-oil of 82.8 % (w/w). The kinetic study denotes that the oil extraction process follows first-order kinetics. The presence of different functional groups, as well as volatile compounds in the extracted oil, were confirmed by fourier-transform infrared spectroscopy and gas chromatography-mass spectrometry. This confirms the presence of 22.11 % of free fatty acid content in the extracted bio-oil. The techno-economic analysis of 4.4 million kg of oil extract plant was investigated. The annual revenue estimated from the oil is 2,097,000 $/yr and the payback period is 5.43 years.

Recycling of pomegranate peel and mandarin peel with ultrasound assisted solvent extraction

According to the data of Food and Agriculture Organization, approximately one third of the food produced in the world (1.6 billion tons/year) is lost when it is not reused at the end of consumption. For the recovery and reuse of valuable ingredients (flavonoids, anthocyanins, phenolic acids) in &amp;amp;lsquo;Katırbaşı&amp;amp;rsquo; pomegranate peel and &amp;amp;lsquo;Satsuma&amp;amp;rsquo; type mandarin peel, which are food industry wastes, ultrasound assisted extraction method (UAEM) which is green technology was used. The effects of various solvents and particle size on extraction yield were investigated by applying solvent / solid ratio of 5 ml/g , particle size of 0.5-1 mm pomegranate peels and 10 min. extraction time for UAEM. The highest efficiency was achieved by using water with 18%. Total phenolic content (TPC) values are 16.55 mg GAE/g dry peel(dp), 14.4 mg GAE/g dp, 12.55 mg GAE/g dp, 10.9 mg GAE/g dp, 14.45 mg GAE/g dp for distilled water, methanol, 50% methanol-water, ethanol, 70% ethanol-water solvents, respectively, for 0.5-1 mm particle size. TPC was found as 11.75 mg GAE/g dp for particle size of 0.25mm and below and 17.5 mg GAE/g dp for the range of particle size of 1-2 mm using water. Also, similar experiments were made for mandarin peels; TPC and AA (Antioxidant Activity, with DPPH) were determined. The parameters were chosen as different solvent type (water, 100% ethanol, 80% ethanol-water, 100% methanol, 80% methanol-water), extraction time (10 and 20 min.) and solvent/solid ratio (10, 20 ml/g) as well. TPC and AA were found 17.8 mg GAE/g dp and 90% for 100% methanol, 10 minutes and 20 ml/g solvent/solid ratio, respectively. When the ultrasound application time was 20 min, TPC and AA were found 18.24 mg GAE/g dp and 90% for 20 ml/g solvent/solid ratio and 80% methanol, respectively. The highest extraction yield was 19% using distilled water for 20 min, 10 ml/g solvent/solid ratio.

Enhanced sodium storage in strongly-combined MoS2/rGO nanocomposite: Constructed by ionic liquid induced layer-by-layer self-assembly

Molybdenum disulfide (MoS2) is a promising anode material for sodium ion battery. Nevertheless, the semi-conductive feature and closely stacked nanostructure hinder its application. Moreover, the uncontrolled geometric structure and loose combination with high-conductive matrix lead to a limited Na+ diffusion path and easy-destroyed structure. Here, a strongly-combined MoS2/rGO nanosheet structure is realized by ionic liquid induced layer-by-layer self-assembly approach. The ionic liquid works well as bi-functional assisted solvent to induce the uniform growth of MoS2 on rGO layers and to maintain the large-scale morphology of rGO nanosheet. The enlarged interlayer distance between S–Mo–S adjacent planes facilitates the fast Na+ transport. The well-maintained rGO layer affords favorable tolerance to the volume change of MoS2 and increases the conductivity as well. Density function theory calculations demonstrate that the enlarged interlayer reduces the diffusion energy barriers of Na+ and accelerates the reaction kinetics. Benefitting from the strong bonding between few-layered MoS2 nanoflake and well-maintained 2D rGO nanosheet, the MoS2/rGO composite exhibits a high specific capacity (581.7 mA h g−1 after 100 cycles at 100 mA g−1), remarkable rate capability (309.2 mA h g−1 at 12.8 A g−1) and excellent cycling stability (263.2 mA h g−1 after 300 cycles at 3 A g−1).

Thermal degradation of bisphenol A and bisphenol S in water and fish (cod and basa) fillets

The thermal degradation of bisphenol A (BPA) and bisphenol S (BPS) was investigated in water and fish (cod, basa) fillets. Ultrasound assisted solvent extraction followed by high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (HPLC-QTOF-MS) was used to analyze residues in fish. Good instrumental linearity (r2 > 0.99) and recoveries (83.3–128.4%) were achieved. BPA and BPS did not degrade (1 h; 100 °C) in water (<0.1% degradation) but degraded in fish matrices. The degradation percentage of BPA was 33.0 ± 1.5% and 35.4 ± 1.2% in incurred and spiked cod, respectively; and the degradation percentage of BPS was 34.7 ± 1.7% and 37.5 ± 1.4% in incurred and spiked basa, respectively. The degradation products in spiked samples were different from those in the incurred group under the same conditions. This first study on the thermal degradation of plastic-related chemicals in food using a non-targeted approach will contribute to the refining of food safety risk assessments.

Determination of phthalates in fish fillets by liquid chromatography tandem mass spectrometry (LC-MS/MS): A comparison of direct immersion solid phase microextraction (SPME) versus ultrasonic assisted solvent extraction (UASE)

Due to the increasing presence of plastic and plastic associated contaminants in the aquatic environments, the monitoring of this contamination in fish products and the understanding of possible human health implications is considered urgent. However, data are still relatively scarce, mostly due to the methodological challenges in the chemical analysis: these contaminants are ubiquitous and procedural contamination from the laboratory is frequent. In this work, we compared solid-phase microextraction (SPME) to ultrasonic assisted solvent extraction (UASE) as sample preparation methods for the liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) determination of phthalates in fish fillets. UASE was carried out with an acetone-hexane (1:1) solution and according to a reference procedure aimed to obtain the exhaustive extraction of the target analytes. SPME was carried out by applying C18 fibers in direct immersion mode and by using water/methanol 20:80 mixture to desorb the aliquot required for the analysis. Overall, SPME displayed an improved control of the background contamination and enabled lower LOQs. Precision, calculated as relative standard deviation (RSD) on replicates of a reference sample, was below 24% for both the method. Analysis of real samples purchased from Italian supermarkets showed that SPME might be an efficient tool for estimating the risk associated with fish consumption.

Development of sample preparation method for organochlorine pesticides analysis in soil samples

OCPs are the persistent organic pollutants which are highly toxic to the environment and can accumulate in humans by foods such as rice, vegetable, and fruits. The aim of this research was to develop a rapid and easy sample preparation method for determination 4 OCPs, aldrin, dieldrin, β-endosulfane, and p-p' DDT in soil samples by gas chromatography with electron capture detection. The analysis was performed by using HP-5 capillary column with the isothermal condition at 250 oC and carrier gas flow rate of 1 mL/min. The results show that the 4 OCPs and internal standard, pentachloronitrobenzene, were analyzed within 6 min. The optimized condition of the sample preparation method was using ultrasonic assisted solvent extraction with 20 mL of hexane and ethyl acetate (9:1 v/v) as an extractant for 15x2 min. The results obtained from the proposed sample preparation method have demonstrated that the limit of detection was 0.628–3.68 μg kg-1. Percent recoveries were in the range of 81.42 to 110.7% and RSD were 1.68–9.43%. Correlation coefficients of calibration graphs were more than 0.99. The developed sample preparation method exhibited simplicity rapid and low chemical reagent consumption with satisfactory results.

Ultrasound assisted solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry for determination of BADGE, BFDGE and their derivatives in packed vegetables

The problem of the presence of trace organic pollutants in food is of growing importance due to increasing awareness about their impact on newborns, infants and adults of reproductive age. Despite the fact that packaged food products offer many advantages, packaging can be a source of contamination for stored food. Thus, monitoring such pollution in food is of high importance. In this work, a novel methodology based on the solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry was applied for the determination of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives in packed vegetables. Several parameters of the extraction process were optimized, including the volume and type of extraction solvent as well as the sonication time. Due to advantages such as simplicity of use, short analysis time, and a reduction in the required amount solvent, the developed procedure can be considered green. In addition, the developed methodology was characterized by good validation parameters. Limit if quantitation (LOQ) was found to be in the range of 0.8 to 1.5 ng/g. The obtained recoveries varied from 78.3% to 111.2%. The repeatability of the extraction ranged between 0.6% and 5.8% (RSD). The proposed method was successfully applied to determine the presence of BADGE, BFDGE and their derivative compounds in the vegetable samples stored in different types of containers. The obtained data indicate that the majority of investigated samples were contaminated by chlorinated and hydroxyl derivatives of BADGE.