Chemical Composition and in vitro Anti-inflammatory Activity of Wheat Germ Oil Depending on the Extraction Procedure.

This study aimed to examine the chemical composition of wheat germ oil extracted by three different methods, and to evaluate its inhibitory effect on the cyclooxygenase and proteinase activities. The results showed that the contents of policosanols, tocopherols and phytosterols were affected by the extraction procedure. However, the fatty acid composition of the different oil extracts was nearly the same. Among the tested oils samples, cold pressed oil exhibited the strongest inhibitory activity against proteinase (93.4%, IC50 =195.7 µg/mL) and cyclooxygenase 1 (80.5%, IC50 =58.6 µg/mL). Furthermore, the cold pressed oil had the highest content of octacosanol, ß-sitosterol and α-linolenic acid, suggesting that those bioactive compounds could be essential for the potent ani-cyclooxygenase activity. The present data revealed that wheat germ oil contained cyclooxygenase and trypsin inhibitors, which are the promising therapeutic target for the treatment of various inflammatory diseases. Thus, wheat germ oil might be used to develop functional foods and pharmaceutic products for the human health.

Comparative Study on Functional Components, Physicochemical Properties and Antioxidant Activity of Amaranthus Caudatus L. Oils Obtained by Different Solvents Extraction.

Functional compositions, physicochemical properties and antioxidant activities of Amaranthus caudatus L. oils (ACO) obtained by different solvents were comparatively investigated. All the resulted ACO were enrich in 75% unsaturated fatty acid and in squalene of about 4 g/100 g. Different solvents showed varying in oil extraction, where acetone results a highest yield of 6.80 g/100 g. ACO extracted by ethanol showed a highest tocopherol (1351.26 mg/kg), polyphenols (211.28 mg/kg) and squalene (42519.13 mg/kg). However, phytosterols in ACO extracted by hexane (27571.20 mg/kg) was higher than that by acetone (19789.91 mg/kg), ethanol (22015.73 mg/kg) and petroleum ether (24763.30 mg/kg). Furthermore, antioxidant activity of ACO was also measured by DPPH, ABTS and FRAP assay. According to principal component and correlation analysis, squalene was correlated with the DPPH scavenging ability, but phytosterols and tocopherols was correlated with the ABTS and ferric reducing ability of the oils, respectively. This study provides a promising excellent source of functional oil for food industries.

Chemistry, oxidative stability and bioactivity of oil extracted from Rosa rugosa (Thunb.) seeds by supercritical carbon dioxide.

Rosa rugosa Thunb. seed oil (RR) extracted by supercritical CO2 was investigated. RR chemical composition, radical scavenging effect and oxidative stability were evaluated. RR aqueous emulsions were examined for cell cytotoxicity, proliferation, redox state and migration using mouse embryonic fibroblast Balb/3T3, human dermal fibroblast NHDF cell lines, and on neoplastic cell lines: acute monocytic leukemia THP-1 and lung adenocarcinoma A549. RR total contents of phytosterols, tocopherols, carotenoids and phenolics were 10115.23, 784.16, 40.32 and 10.30 mg/kg, respectively. Rich antioxidant composition of RR was reflected in its high antioxidant activity (2.1 mM/kg Trolox equivalent) as well as oxidative stability (activation energy 105.6 kJ/mol). The RR emulsions led to marked augmentation of the total cell protein content in BALB/3T3 and NHDF cultures, inhibited cancer cell migration and reduced ROS formation. The studied RR oil proved to have a remarkable combination of bioactive compounds and to exert an antioxidative and chemopreventive effects.

Application of response surface methodology (RSM) for the optimization of supercritical CO2 extraction of oil from patè olive cake: Yield, content of bioactive molecules and biological effects in vivo.

The two-phase technology for olive oil extraction generates large amounts of patè olive cake (POC), a by-product that is rich in bioactive health-promoting compounds. Here, response surface methodology (RSM) was used to maximize supercritical-CO2 oil extraction from POC, while minimizing operative temperature, pressure and time. Under the optimal parameters (40.2 °C, 43.8 MPa and time 30 min), the oil yield was 14.5 g·100 g-1 dw (~65% of the total oil content of the freeze-dried POC matrix), as predicted by RSM. Compared with freeze-dried POC, the oil contained more phytosterols (13-fold), tocopherols (6-fold) and squalene (8-fold) and was a good source of pentacyclic triterpenes. When the biological effects of POC oil intake (20-40 µL·die-1) were evaluated in the livers of BALB/c mice, no significant influence on redox homeostasis was observed. Notably, a decline in liver triglycerides alongside increased activities of NAD(P)H:Quinone Oxidoreductase 1, Carnitine Palmitoyl-CoA Transferase and mitochondrial respiratory complexes suggested a potential beneficial effect on liver fatty acid oxidation.

Effect of different processing methods on physicochemical properties, chemical compositions and in vitro antioxidant activities of Paeonia lactiflora Pall seed oils.

A research was performed to determine and compare the physicochemical properties, chemical compositions and in vitro antioxidant activities of Paeonia lactiflora Pall seed oils with ultrasonic-assisted solvent extraction, pressing and supercritical fluid extraction. Paeonia lactiflora Pall seed oil contained a high percentage of polyunsaturated fatty acids and monounsaturated fatty acids, especially oleic (31.62-32.88%) and α-linolenic acids (37.55-39.95%). The beneficial multiple dietary phytochemicals (tocopherol, phytosterols and squalene) and in vitro antioxidant activity were significantly influenced by the hull and processing method (P＜0.05). However, higher tocopherol (596.67-738.76 mg/kg) and phytosterols (5775.01-6055.62 mg/kg) contents were found in supercritical fluid extraction oils. Additionally, ten individual polyphenols were quantified, and significantly influenced by the hull and processing method (P＜0.05), with the content of benzoic acid and several individual flavonoids being the higher. According to the results, pressing might be the best process for extracting oil with a high number of polyphenols.

Efficient separation of tocopherol homologues in vegetable oil by ionic-liquid-based countercurrent chromatography using a non-aqueous biphasic system.

Tocopherol homologues are important fat-soluble bioactive compounds with high nutritional value. However, it is of great challenge to separate these homologues because of their high structural similarities. In this work, ionic-liquid-based countercurrent chromatography was used for the separation and purification of tocopherol homologues. Conventional countercurrent chromatography and ionic-liquid-based countercurrent chromatography solvent systems were evaluated in respect of partition coefficient, separation factor, and stationary phase retention factor to separate these targets. Kind of ionic liquids, amount of ionic liquid, and sample amount were systematically optimized. A novel countercurrent chromatography non-aqueous biphasic system composed of n-hexane-methanol-1-butyl-3-methylimidazolium chloride was established. The baseline separation of tocopherol mixtures was obtained in one cycle process. The ionic liquid played a key role in the countercurrent chromatography separation, which resulted in difference of partition behavior of individual tocopherol in the whole system through different hydrogen-bonding affinity. Finally, n-hexane-methanol-1-butyl-3-methylimidazolium chloride (5:5:3, v/v) water-free biphasic system was successfully applied to separate tocopherol homologues from vegetable oil that was not achieved beforehand. This method can be widely employed to separate many similar molecules such as tocotrienols, tocomonoenols, and marine-derived tocopherol in food samples.

Jabuticaba residues (Myrciaria jaboticaba (Vell.) Berg) are rich sources of valuable compounds with bioactive properties.

Jabuticaba (Myrciaria jaboticaba (Vell.) Berg) is a Brazilian berry, very appreciated for in natura consumption. However, its epicarp is not normally consumed due to its stiffness and astringent taste, and in manufacture of products from jabuticaba fruit, it is responsible for the generation of large amounts of residues. The exploration of by-products is becoming important for the obtainment of valuable bioactive compounds for food and pharmaceutical industries. In this context, jabuticaba epicarp was studied regarding its chemical composition, namely in terms of phenolic compounds, tocopherols, and organic acids, and its bioactive properties, such as antioxidant, anti-proliferate, anti-inflammatory, and antimicrobial activities. A total of sixteen phenolic compounds, four tocopherols and six organic acids were identified in jabuticaba epicarp. Regarding bioactive properties, it showed high antioxidant activity, also presenting moderate anti-inflammatory, anti-proliferative, and antimicrobial activities. The extract did not present hepatotoxicity, confirming the possibility of its applications without toxicity issues.

Extraction of Tocopherol from Soybean Oil Deodorizer Distillate by Deep Eutectic Solvents.

Natural tocopherols have strong antioxidant and physiological functions, which are mainly produced from vegetable oil deodorized distillates. In this work, a simple and green solvent extraction method based on deep eutectic solvent has been developed to simultaneously extract three isomers of tocopherols (α, γ and δ-tocopherols) from soybean oil deodorizer distillate (SODD). The key factor to affect the solvent extraction efficiency was proposed that phenolic deep eutectic solvents interacted with targeted tocopherols mainly through π-π bonds interaction. This sustainable extraction process included two steps. Firstly, total tocopherols were extracted from SODD at room temperature by phenolic deep eutectic solvent composed of ChCl and p-cresol. Subsequently, tocopherols were successfully separated from deep eutectic solvent phase by re-extraction with n-hexane, and tocopherols products could be simply recovered. Under the optimum extraction conditions, the extraction efficiency of total tocopherols (α, γ and δ-tocopherols) from SODD was 77.6% after extraction with phenolic deep eutectic solvent.

Simultaneous determination of tocopherols, carotenoids and phytosterols in edible vegetable oil by ultrasound-assisted saponification, LLE and LC-MS/MS.

A method was developed to simultaneously determine eight bioactive compounds in edible oil based on ultrasound-assisted saponification, liquid-liquid extraction and liquid chromatography coupled with tandem mass spectrometry. Central composite design was employed to optimize ultrasonic temperature and time of saponification. Sample treatment was conducted by ultrasound-assisted saponification at temperature of 75 °C for 40 min. Limits of detection and limits of quantification ranged from 2.0 to 3.2 and from 6.1 to 10.0 ng/mL, respectively. Linear correlations were obtained (R2 > 0.99) and the recoveries at three spiked levels were between 81.7% and 112.0%. This method was employed to determine eight compounds in camellia oils and olive oils. As results, the contents of stigmasterol, δ-tocopherol, γ-tocopherol, ß-carotene and lutein in camellia oils were significantly higher than those in olive oils (p < 0.05). The proposed method can be successfully used to determination of these eight active compounds in camellia oil and other edible oils.

Physico-chemical Characterization, Profiling of Total Lipids and Triacylglycerol Molecular Species of Omega-3 Fatty Acid Rich B. arvensis Seed Oil from India.

Buglossoides arvensis is indigenous to India and its seed oil is rich in unique and nutritionally important omega-3 fatty acid namely, stearidonic acid (SDA). It is a non-conventional oil seed plant and needs to be agronomically adapt for commercial utilization. In the present study, oil extracted from the agronomically adapted high yielding cultivar of B. arvensis seeds was analyzed for its oil content, fatty acid (FA) composition, physico-chemical characteristics, total lipids and triacylglycerol molecular species. The oil content, peroxide, acid, iodine, p-anisidine values and tocopherol content of the oil were 18.53% (w/w), 2.06 meq of active oxygen / kg of oil, 2.55 mg KOH/g oil, 217.2 g I2/100g oil, 10.7 and 774.8 mg/kg oil respectively. Oxidative stability as determined by the induction period was found to be 3.1 h. Polyunsaturated fatty acid (PUFA) content of the oil was 81.3% (of total FA), comprising of α-linolenic acid (ALA; 48.5%), SDA (18.6%), linoleic acid (LA; 10.3%) and γ-linolenic acid (GLA; 3.9%). Profiling of lipid classes showed neutral lipids (89.3%, w/w) as most abundant lipid class followed by glycolipids (7.4%, w/w) and phospholipids (3.3%, w/w). High resolution mass spectrometric analysis of triacylglycerol (TAG) molecular species showed TAGs with C54 carbons in the acyl chain as most abundant. Positional distribution analysis showed GLA and SDA predominantly at the sn-2 position of triacylglycerol. FTIR analysis revealed common characteristics molecular features similar to PUFA rich oils. Overall, the results suggest that B. arvensis seed oil is an excellent ω3-ω6-ω3 or ALA-SDA-GLA source for food and nutraceutical industries.

Effect of refining on bioactive composition and oxidative stability of hazelnut oil.

In this study, the effect of refining process on the content of phytochemicals, antioxidant capacity and oxidative stability of hazelnut oil was investigated. The oil samples were taken at the consecutive steps of hazelnut refining process and analyzed for some compositional properties along with the antioxidant capacity and oxidative stability. The results have shown that, carotenoid content of the hazelnut oil was decreased during the refining process. The main carotenoids of hazelnut oil were found to be lutein and zeaxanthin and these compounds were lost completely during bleaching step of the refining. On the other hand, phenolic compounds and tocopherols were also partly removed from hazelnut oil to a degree. Loses in antioxidant compounds caused a clear decrease in antioxidant capacity measured in either the oils or polar extract of oils. Oxidative stability of the oil samples was measured by Rancimat method and it was found that neutralization caused an increase in oxidative stability compared to the crude oil. However, deodorization step caused a slight decrease in oxidative stability probably as a result of partial removal of tocopherols at this stage.

Cytotoxicity of new secondary metabolites, fatty acids and tocols composition of seeds of Ducrosia anethifolia (DC.) Boiss.

Two new monoterpene Ducrosin A (1) and sesquiterpene Ducrosin B (2) were isolated along with three known compounds, stigmasterol (3) and two furanocoumarins (4 and 5), from the dichloromethane extract of the seeds of Ducrosia anethifolia (DC.) Boiss. Their structures were determined using extensive 1D and 2D NMR, (ES)-HRMS and IR spectroscopic analyses and by comparison with literature data. Gas chromatography analysis of the fatty acids (FAs) of D. anethifolia seed oils (DAOs) showed high percentages of elaidic acid (C18:1 Δ9t) 65% and oleic acid (C18:1 Δ9c) 15%. The total tocopherol (tocols) content in DAOs was found to be 164 mg/100 g. The cytotoxic effect of the isolates was also evaluated using the MTT assay against the HCT-116 and SKOV-3 cell lines. The results showed that compound 2 was the most cytotoxic agent followed by compounds 1 and 4, which has an epoxide moiety that most likely contributes to its activity.

The Effect of Solvent Type and Roasting Processes on Physico-Chemical Properties of Tigernut (Cyperus esculentus L.) Tuber Oil.

In this study, physico-chemical properties of raw and roasted tigernut oils extracted by two different solvents were determined. Peroxide values of raw and roasted tigernut oils extracted by petroleum ether and n-hexane solvents changed between 0.83 and 0.91 meqO2/100g to 1.57 and 1.63 meqO2/100g, respectively. While oleic acid contents of raw tigernut oils extracted by petroleum ether and n-hexane are determined as 66.83 and 67.47%, oleic acid contents of roasted tigernut oils extracted by petroleum ether and n-hexane were determined as 67.08 and 68.16%, respectively. The highest δ-tocopherol content was found in raw tigernut oil extracted by petroleum ether (54.91 mg/100g), while the lowest level is determined in roasted tigernut oil by n-hexane (50.77 mg/100g). As a result, the fatty acid profiles of roasted tigernut oil extracted by n-hexane were higher compared to results of raw tigernut oils extracted by petroleum ether (p < 0.05).

The Effect of Pressure and Solvent on the Supercritical Fluid Chromatography Separation of Tocol Analogs in Palm Oil.

There are six tocol analogs present in palm oil, namely α-tocopherol (α-T), α-tocomonoenol (α-T1), α-tocotrienol (α-T3), γ-tocotrienol (γ-T3), ß-tocotrioenol (ß-T3) and δ-tocotrienol (δ-T3). These analogs were difficult to separate chromatographically due to their similar structures, physical and chemical properties. This paper reports on the effect of pressure and injection solvent on the separation of the tocol analogs in palm oil. Supercritical CO2 modified with ethanol was used as the mobile phase. Both total elution time and resolution of the tocol analogs decreased with increased pressure. Ethanol as an injection solvent resulted in peak broadening of the analogs within the entire pressure range studied. Solvents with an eluent strength of 3.4 or less were more suitable for use as injecting solvents.

More than 170 polyunsaturated tocopherol-related compounds in a vitamin E capsule: Countercurrent chromatographic enrichment, gas chromatography/mass spectrometry analysis and preliminary identification of the potential artefacts.

Tocopherols and tocotrienols (usually summed up as vitamin E) are a class of structurally related natural antioxidants. Commonly, only some of the eight classic representatives (four tocopherols and four tocotrienols) are found with varied composition in food. In this study we fractionated 230mg oil from commercial vitamin E supplement capsules by countercurrent chromatography (CCC) and subsequent analysis by gas chromatography with mass spectrometry (GC/MS) of silylated CCC fractions showed that these eight isomers represented only about 70% of total tocopherol compounds. Detailed analysis enabled the detection of 161T3 isomers (α-, γ- and δ-T3) along with 18 tetra- and several penta-unsaturated isomers (tocools), two tocomonoenol isomers, and several degradation products with shorter isoprenoid side chain (apo-tocools). Altogether, over 170 tocool compounds, most likely artefacts which originated from an inappropriate oil refining process were described in this study. Silver ion high performance liquid chromatography (Ag+-HPLC) was used to separate one fraction rich in γ-T3 into four peaks each consisting of at least five peaks according to GC/MS. About ten γ-T3 isomers were also detected in rice bran oils from one producer bought retail in Germany.

Bioactive Compounds of Cold-pressed Thyme (Thymus vulgaris) Oil with Antioxidant and Antimicrobial Properties.

Herbs rich in bioactive phytochemicals were recognized to have biological activities and possess many health-promoting effects. In this work, cold-pressed thyme (Thymus vulgaris L.) oil (TO) was studied for its lipid classes, fatty acid profile, tocols and phenolics contents. Antioxidant activity and radical scavenging potential of TO against free radicals (DPPH(・) and galvinoxyl) was determined. Antimicrobial activity (AA) of TO against food borne bacteria, food spoilage fungi and dermatophyte fungi were also evaluated. Neutral lipids accounted for the main lipid fraction in TO, followed by glycolipids and phospholipids. The major fatty acids in TO were linoleic, oleic, stearic, and palmitic. γ-Tocopherol (60.2% of total tocols) followed by α-tocotrienol (26.9%) and α-tocopherol (9.01% of total tocols) were the main tocols. TO contained high amounts of phenolic compounds (7.3 mg/g as GAE). TO had strong antiradical action wherein 65% of DPPH(・) radicals and 55% of galvinoxyl radical were quenched after 60 min of incubation. Rancimat assay showed that induction time (IT) for TO: sunflower oil blend (1:9, w/w) was 6.5 h, while TO: sunflower oil blend (2:8, w/w) recorded higher IT (9 h). TO inhibited the growth of all tested microorganisms. TO exhibited various degrees of AA against different food borne bacteria, food spoilage fungi and dermatophyte fungi, wherein the highest AA was recorded against dermatophyte fungi and yeasts including T. mentagrophytes (62 mm), T. rubrum (40 mm), and C. albicans (20 mm) followed by food spoilage fungi including A. flavus (32 mm) with minimal lethal concentrations (MLC) ranging between 80 to 320 µg/mL. Furthermore, TO exhibited broad-spectra activity against food borne bacteria including S. aureus (30 mm), E. coli (25 mm) and L. Monocytogenes (20 mm) with MLC ranging between 160 to 320 µg/mL. The results suggest that TO could be used economically as a valuable natural product with novel functional properties in food, cosmetics and pharmaceutical industries.

A simultaneous quantitative method for vitamins A, D and E in human serum using liquid chromatography-tandem mass spectrometry.

Non-classical roles of fat-soluble vitamins (FSVs) in many pathologies including cancer have been identified. There is also evidence of hormonal interactions between two of these vitamins, A and D. As a result of this enhanced clinical association with disease, translational clinical research and laboratory requests for FSV measurement has significantly increased. However there are still gaps in the analytical methods available for the measurement of these vitamins. This study aimed to develop a method for simultaneous quantification of 25-hydroxyvitamin-D2 (25-OHD2), 25-hydroxyvitamin-D3 (25-OHD3) and its 3-epimer (epi-25-OHD3), retinol and α-tocopherol in human serum using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The procedure was developed and validated across two LC-MS/MS platforms, using commercial calibrators referenced to certified reference materials, controls, and deuterated internal standards. The samples were prepared by liquid-liquid extraction prior to injection and LC separation (using a Pursuit-PFP column) on two Agilent MS/MS systems (6410 and 6490) in electrospray ionisation positive mode with multiple reaction monitoring. Identification and quantification of 25-OHD3 from its 3-epimer as well as 25-OHD2, retinol and α-tocopherol were achieved. The dynamic ranges were 4-160 nmol/L for 25-OHD2 and epi-25-OHD3, 4-200 nmol/L for 25-OHD3, 0.1-4.0µmol/L for retinol and 4-70µmol/L for α-tocopherol with correlation (r(2)) of 0.997-0.998. Based on participation in an external quality assurance program, the overall performance of the simultaneous methods were: imprecision (CV%) and inaccuracy (average bias) 3.0% and 3.2 nmol/L, respectively, for 25-OHD3; 5.0% and 0.04µmol/L, respectively, for retinol; and 4.7% and 0.2µmol/L, respectively, for α-tocopherol. In summary, two simple LC-MS/MS methods were successfully developed and validated for the simultaneous quantification of the three vitamin D metabolites (25-OHD2, 25-OHD3 and 3-epimer of 25-OHD3), vitamin A (retinol) and vitamin E (α-tocopherol) in serum.

Antioxidant Compounds from Vegetable Matrices: Biosynthesis, Occurrence, and Extraction Systems.

Natural antioxidants such as vitamin C, tocopherols and tocotrienols, carotenoids, and phenolic compounds are largely distributed in plant products. Most of them are not synthesized by human and need to be introduced with diet according to the Recommended Daily Intake (RDI). This work was aimed to give a comprehensive overview on the occurrence of these antioxidants in plants, in particular in plant foods, on the mechanisms of biosynthesis, and on conventional (liquid-liquid or solid-liquid extraction, Soxhlet) and innovative (enzymatic-assisted, pressurized fluid, supercritical fluid, ultrasound-assisted, microwave-assisted, pulsed electric field) extraction systems.

A new 9,10-dihydrophenanthrene and cell proliferative 3,4-δ-dehydrotocopherols from Stemona tuberosa.

A new compound, 9,10-dihydro-5-methoxy-8-methyl-2,7-phenanthrenediol (1), was isolated from the roots of Stemona tuberosa Lour. (Stemonaceae) together with two new optically active compounds, (2S,4'R,8'R)-3,4-δ-dehydrotocopherol (2) and (2R,4'R,8'R)-3,4-δ-dehydrotocopherol (3). The structures of compounds 1-3 were determined on the basis of spectroscopic data analysis. Compounds 2 and 3 were each purified from a stereoisomeric mixture of 2 and 3 by preparative HPLC using a chiral column for the first time. The absolute configurations at C-2 of 2 and 3 were determined by Circular Dichroism (CD) experiments. As a part of the research to find natural wound healing agents, all isolates and the mixture of 2 and 3 were evaluated for their cell proliferative effects using a mouse fibroblast NIH3T3 and a HeLa human cervical cancer cell line. As a result, 1, 2, 3, or the mixture of 2 and 3 showed 41.6%, 78.4%, 118.6%, 38.2% increases of cell proliferation in the mouse fibroblast NIH3T3 respectively, compared to 28.4% increase of δ-tocopherol. Moreover, none of them induced cancer cell proliferation. Therefore, 3,4-δ-dehydrotocopherols, especially pure isomers 2 and 3 can be suggested as potential wound healing agents.

Quantification of tocopherols and tocotrienols in soybean oil by supercritical-fluid chromatography coupled to high-resolution mass spectrometry.

For the most effective analytical strategies, development and validation include optimization of such analytical variables as resolution, detectability, sensitivity, simplicity, cost effectiveness, flexibility, and speed. However, other aspects concerning operator safety and environmental impact are not considered at the same level. The result has been many unintended negative effects of analytical methods developed to investigate different kinds of sample, especially hydrophobic compounds that generate a large amount of chemical waste and have a strong negative environmental impact. In this context, quantification of tocopherols and tocotrienols, i.e. the vitamin E family, is usually achieved by normal-phase liquid chromatography using large volumes of toxic organic solvents, or reversed-phase liquid chromatography using a high percentage of methanol for elution. We propose here a "greener" analytical strategy, including the hyphenation of supercritical-fluid chromatography, using CO2 and ethanol as mobile phase, NH2 as stationary phase, and mass spectrometry for the detection and quantification of vitamin E congeners in soybean oil. An atmospheric-pressure photoionization (APPI) source seemed significantly more sensitive and robust than electrospray or atmospheric-pressure chemical ionization (APCI). This method led to shortened analysis time (less than 5 min) and was revealed to be as sensitive as more traditional approaches, with limits of detection and quantification in the tens of µg L(-1).