Ionic Liquids as Designed, Multi-Functional Plasticizers for Biodegradable Polymeric Materials: A Mini-Review

Measures to endorse the adoption of eco-friendly biodegradable plastics as a response to the scale of plastic pollution has created a demand for innovative products from materials from Nature. Ionic liquids (ILs) have the ability to disrupt the hydrogen bonding network of biopolymers, increase the mobility of biopolymer chains, reduce friction, and produce materials with various morphologies and mechanical properties. Due to these qualities, ILs are considered ideal for plasticizing biopolymers, enabling them to meet a wide range of specifications for biopolymeric materials. This mini-review discusses the effect of different IL-plasticizers on the processing, tensile strength, and elasticity of materials made from various biopolymers (e.g., starch, chitosan, alginate, cellulose), and specifically covers IL-plasticized packaging materials and materials for biomedical and electrochemical applications. Furthermore, challenges (cost, scale, and eco-friendliness) and future research directions in IL-based plasticizers for biopolymers are discussed.

Multifunctional fully biobased aerogels for water remediation: Applications for dye and heavy metal adsorption and oil/water separation

Water ecosystem contamination from industrial pollutants is an emerging threat to both humans and native species, making it a point of global concern. In this work, fully biobased aerogels (FBAs) were developed by using low-cost cellulose filament (CF), chitosan (CS), citric acid (CA), and a simple and scalable approach, for water remediation applications. The FBAs displayed superior mechanical properties (up to ∼65 kPa m³ kg^-1 specific Young's modulus and ∼111 kJ/m³ energy absorption) due to CA acting as a covalent crosslinker in addition to the natural hydrogen bonding and electrostatic interactions between CF and CS. The addition of CS and CA increased the variety of functional groups (carboxylic acid, hydroxyl and amines) on the materials' surface, resulting in super-high dye and heavy metal adsorption capacities (619 mg/g and 206 mg/g for methylene blue and copper, respectively). Further modification of FBAs with a simple approach using methyltrimethoxysilane endowed aerogel oleophilic and hydrophobic properties. The developed FBAs showed a fast performance in water and oil/organic solvents separation with more than 96% efficiency. Besides, the FBA sorbents could be regenerated and reused for multiple cycles without any significant impact on their performance. Moreover, thanks to the presence of amine groups by addition of CS, FBAs also displayed antibacterial properties by preventing the growth of Escherichia coli on their surface. This work demonstrates the preparation of FBAs from abundant, sustainable, and inexpensive natural resources for applications in wastewater purification.

Renewable Biopolymers Combined with Ionic Liquids for the Next Generation of Supercapacitor Materials

The search for biocompatible and renewable materials for the next generation of energy devices has led to increasing interest in using biopolymers as a matrix component for the development of electric double-layer capacitors (EDLCs). However, using biopolymers as host matrices presents limitations in performance and scalability. At the same time, ionic liquids (ILs) have shown exceptional properties as non-aqueous electrolytes. This review intends to highlight the progress in integrating ILs and biopolymers for EDLC. While ILs have been used as solvents to process biopolymers and electrolyte materials, biopolymers have been utilized to provide novel chemistries of electrolyte materials via one of the following scenarios: (1) acting as host polymeric matrices for IL-support, (2) performing as polymeric fillers, and (3) serving as backbone polymer substrates for synthetic polymer grafting. Each of these scenarios is discussed in detail and supported with several examples. The use of biopolymers as electrode materials is another topic covered in this review, where biopolymers are used as a source of carbon or as a flexible support for conductive materials. This review also highlights current challenges in materials development, including improvements in robustness and conductivity, and proper dispersion and compatibility of biopolymeric and synthetic polymeric matrices for proper interface bonding.

Ionic Liquids as Tools to Incorporate Pharmaceutical Ingredients into Biopolymer-Based Drug Delivery Systems

This mini-review focuses on the various roles that ionic liquids (ILs) play in the development and applications of biopolymer-based drug delivery systems (DDSs). Biopolymers are particularly attractive as drug delivery matrices due to their biocompatibility, low immunogenicity, biodegradability, and strength, whereas ILs can assist the formation of drug delivery systems. In this work, we showcase the different strategies that were explored using ILs in biopolymer-based DDSs, including impregnation of active pharmaceutical ingredients (APIs)-ILs into biopolymeric materials, employment of the ILs to simplify the process of making the biopolymer-based DDSs, and using the ILs either as dopants or as anchoring agents.

Deep Eutectic Solvents: Alternative Solvents for Biomass-Based Waste Valorization

Innovative technologies can transform what are now considered “waste streams” into feedstocks for a range of products. Indeed, the use of biomass as a source of biopolymers and chemicals currently has a consolidated economic dimension, with well-developed and regulated markets, in which the evaluation of the manufacturing processes relies on specific criteria such as purity and yield, and respects defined regulatory parameters for the process safety. In this context, ionic liquids and deep eutectic solvents have been proposed as environmentally friendly solvents for applications related to biomass waste valorization. This mini-review draws attention to some recent advancements in the use of a series of new-solvent technologies, with an emphasis on deep eutectic solvents (DESs) as key players in the development of new processes for biomass waste valorization. This work aims to highlight the role and importance of DESs in the following three strategic areas: chitin recovery from biomass and isolation of valuable chemicals and biofuels from biomass waste streams.

Phase Behavior of Aqueous Biphasic Systems with Choline Alkanoate Ionic Liquids and Phosphate Solutions: The Influence of pH

Aqueous biphasic systems (ABS) composed of the choline alkanoate ionic liquids (ILs) choline acetate [Cho][OAc], choline propanoate [Cho][Pro], choline butyrate [Cho][But], and choline hexanoate [Cho][Hex], mixed with K3PO4 solutions at pH 7.2 and 14.5, were prepared and their phase diagrams were compared. The ability to form ABS with alkaline K3PO4 solutions decreased in the order [Cho][OAc] ≈ [Cho][Pro] > [Cho][But] > [Cho][Hex], while with neutral K3PO4 solutions, [Cho][OAc] could not form an ABS, and the other three ILs performed similarly. All of the biphasic regions of the ABS decreased with the increase in pH. 1H-NMR data indicated anion exchange between phases in ABS at neutral pH. The ABS at neutral pH were evaluated to extract the triazine herbicides simazine, cyanazine, and atrazine, and the ABS formed by [Cho][Pro] and the pH 7.2 K3PO4 solution has shown extraction recoveries higher than 90%.

PRRSV detection by qPCR in processing fluids and serum samples collected in a positive stable breeding herd following mass vaccination of sows with a modified live vaccine

In the last two decades, in France, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) stabilization protocols have been implemented using mass vaccination with a modified live vaccine (MLV), herd closure and biosecurity measures. Efficient surveillance for PRRSV is essential for generating evidence of absence of viral replication and transmission in pigs. The use of processing fluid (PF) was first described in 2018 in the United States and was demonstrated to provide a higher herd-level sensitivity compared with blood samples (BS) for PRRSV monitoring. In the meantime, data on vertical transmission of MLV viruses are rare even as it is a major concern. Therefore, veterinarians usually wait for several weeks after a sow mass vaccination before starting a stability monitoring. This clinical study was conducted in a PRRSV-stable commercial 1000-sow breed-to-wean farm. This farm suffered from a PRRS outbreak in January 2018. After implementing a stabilisation protocol, this farm was controlled as stable for more than 9 months before the beginning of the study. PF and BS at weaning were collected in four consecutive batches born after a booster sow mass MLV vaccination. We failed to detect PRRSV by qPCR on PF and BS collected in a positive-stable breeding herd after vaccination with ReproCyc® PRRS EU (Boehringer Ingelheim, Ingelheim, Germany).

Use of Ionic Liquids in Chitin Biorefinery: A Systematic Review

Lignocellulosic biomass biorefinery is the most extensively investigated biorefinery model. At the same time, chitin, structurally similar to cellulose and the second most abundant polymer on Earth, represents a unique chemical structure that allows the direct manufacture of nitrogen-containing building blocks and intermediates, a goal not accomplishable using lignocellulosic biomass. However, the recovery, dissolution, and treatment of chitin was fairly challenging until the polymer's easy dissolution in ionic liquids (salts that are liquid at room temperature) was discovered. In this systematic review, we highlight recent developments in the processing of chitin, with a particular emphasis placed on methods conducted with the help of ionic liquids used as solvents, co-solvents, or catalysts. Such use of ionic liquids in the field of chemical transformations of chitin not only allows for shorter times and less harsh reaction conditions, but also results in different outcomes and higher product yields when compared with reactions conducted in "traditional" manner. Valorization of biomass in general, and chitin in particular, is a key enabling strategy of the circular economy, due to the importance of the sustainable production of biomass-based goods and chemicals and full chain resource efficiency. Economics is driven by the production of high-value chemicals or chemical intermediates from various biomasses, and chitinous biomass is a valuable potential resource. A fundamental "paradigm shift" will radically change the balance of oil-based chemicals to biopolymer-based chemicals, and chitin valorization is a necessary step aimed toward its full market competitiveness and flexibility.

Solubility Studies of Cyclosporine Using Ionic Liquids

Six ionic liquids (ILs) were selected based on their chemical and physical properties to study the solubility of cyclosporine A. Of these, cyclosporine exhibited higher room temperature solubility in 1-ethyl-3-methylimidazolium acetate ([C₂mim][OAc]) than in acetone, an effective molecular solvent used to solubilize and purify cyclosporine. The solubility of cyclosporine in the ILs dramatically increased at higher temperatures, a critical factor that cannot be varied in a wide range with low boiling molecular solvents. The differences in solubility were explored for cyclosporine purification. Cyclosporine was purified up to ∼93% with n-butylammonium acetate ([C₄NH₃][OAc]) and could be further purified to 95% using an IL/organic solvent biphasic system. After purification, cyclosporine was recovered as an amorphous solid using the ILs.

Polyoxometalate catalysts for biomass dissolution: understanding and design

The use of polyoxometalate catalysts for selective delignification of biomass presents a possible route toward using ionic liquids (ILs) to efficiently obtain high-molecular weight biopolymers from biomass. Rapid progress in this area will depend on recognizing and using the link with already well-developed inorganic chemistry in ILs pursued outside the field of biomass processing. Here, we use crystal structures determined from single crystal X-ray diffraction to better understand the behavior of [PV2Mo10O40]5-, a polyoxometalate catalyst known for its ability to promote selective delignification of biomass in the IL 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]). The crystal structure of [C2mim]5[PV2Mo10O40]·THF shows the formation of cationic shells around the anions which are likely representative of the interactions of this catalyst with [C2mim][OAc] itself. The reaction of NH4VO3 with [C2mim][OAc] is explored to better understand the chemistry of vanadium(V), which is critical to redox catalysis of [PV2Mo10O40]5-. This reaction gives crystals of [C2mim]4[V4O12], showing that this IL forms discrete metavanadates which are obtained from aqueous solutions in a specific pH range and indicating that the basicity of [OAc]- dominates the speciation of vanadium (V) in this IL.

Porphyrinic Ionic Liquid Dyes: Synthesis and Characterization

Four porphyrinic ionic liquids and four higher melting salts (>100 °C) were synthesized as potential photosensitizers from highly symmetric porphyrins by introducing alkyl chains and exchanging anions to tune their solubility and singlet oxygen generation capability. Among the synthesized compounds was 5,10,15,20-tetra(4-dodecylpyridinum)porphyrin tetrakis-bis(trifluoromethylsulfonyl)-amide, a room-temperature ionic liquid that could be crystallized as a solvate with nitrobenzene.

Nanodarts, nanoblades, and nanospikes: Mechano-bactericidal nanostructures and where to find them

Over the past ten years, a next-generation approach to combat bacterial contamination has emerged: one which employs nanostructure geometry to deliver lethal mechanical forces causing bacterial cell death. In this review, we first discuss advances in both colloidal and topographical nanostructures shown to exhibit such "mechano-bactericidal" mechanisms of action. Next, we highlight work from pioneering research groups in this area of antibacterials. Finally, we provide suggestions for unexplored research topics that would benefit the field of mechano-bactericidal nanostructures. Traditionally, antibacterial materials are loaded with antibacterial agents with the expectation that these agents will be released in a timely fashion to reach their intended bacterial metabolic target at a sufficient concentration. Such antibacterial approaches, generally categorized as chemical-based, face design drawbacks as compounds diffuse in all directions, leach into the environment, and require replenishing. In contrast, due to their mechanisms of action, mechano-bactericidal nanostructures can benefit from sustainable opportunities. Namely, mechano-bactericidal efficacy needs not replenishing since they are not consumed metabolically, nor are they designed to release or leach compounds. For this same reason, however, their action is limited to the bacterial cells that have made direct contact with mechano-bactericidal nanostructures. As suspended colloids, mechano-bactericidal nanostructures such as carbon nanotubes and graphene nanosheets can pierce or slice bacterial membranes. Alternatively, surface topography such as mechano-bactericidal nanopillars and nanospikes can inflict critical membrane damage to microorganisms perched upon them, leading to subsequent cell lysis and death. Despite the infancy of this area of research, materials constructed from these nanostructures show remarkable antibacterial potential worthy of further investigation.

Ionic liquids in cross-coupling reactions: “liquid” solutions to a “solid” precipitation problem

To alleviate the problem of solid salt precipitation when using inorganic bases in cross-coupling reactions, basic anions were combined with the trihexyl(tetradecyl)phosphonium ([P₆₆₆₁₄]⁺) cation to ensure an ionic liquid byproduct.

Transdermal Bioavailability in Rats of Lidocaine in the Forms of Ionic Liquids, Salts, and Deep Eutectic

Tuning the bioavailability of lidocaine was explored by its incorporation into the ionic liquid lidocainium docusate ([Lid][Doc]) and the deep eutectic Lidocaine·Ibuprofen (Lid·Ibu) and comparing the transdermal absorption of these with the crystalline salt lidocainium chloride ([Lid]Cl). Each form of lidocaine was dissolved in a vehicle cream and topically applied to Sprague-Dawley rats. The concentrations of the active pharmaceutical ingredients (APIs) in blood plasma were monitored over time as an indication of systemic absorption. The concentration of lidocaine in plasma varied between applied API-based creams, with faster and higher systemic absorption of the hydrogen bonded deep eutectic Lid·Ibu than the absorption of the salts [Lid]Cl or [Lid][Doc]. Interestingly, a differential transdermal absorption was observed between lidocaine and ibuprofen when Lid·Ibu was applied, possibly indicating different interactions with the tissue components.

Determination of polybrominated diphenyl ethers in milk samples. Development of green extraction coupled techniques for sample preparation

Ultrasound-assisted extraction (UAE), cloud point extraction (CPE), and ultrasound back-extraction (UABE) techniques have been coupled for lixiviation, preconcentration, and cleanup of polybrominated diphenyl ethers (PBDEs) from milk samples for determination by gas chromatography-electron capture detection (GC-ECD). Physicochemical parameters that affect the efficiency of the extraction system were investigated using a design of experiments based on multivariate statistical tools, and considering the sample matrix along the development. The coupling of the leaching step, UAE, enhanced ca. 3.5 times the extraction efficiency of the former sample preparation methodology (CPE-UABE) leading to cleaner sample extracts suitable for GC analysis. Under optimum conditions, the proposed methodology exhibits successful performance in terms of linearity and precision, with recoveries in the range of 68-70% and LODs within the range 0.05-0.5 ng/g dry weight (d.w.). The proposed sample preparation methodology coupled three green analytical techniques. It expands the application frontiers of CPE for the analysis of biological samples by GC. The optimized methodology was used for determination of PBDEs in powder milk samples, from both commercial and human sources.

Efficient dehydration and recovery of ionic liquid after lignocellulosic processing using pervaporation

BACKGROUND

Biomass pretreatment using certain ionic liquids (ILs) is very efficient, generally producing a substrate that is amenable to saccharification with fermentable sugar yields approaching theoretical limits. Although promising, several challenges must be addressed before an IL pretreatment technology can become commercially viable. One of the most significant challenges is the affordable and scalable recovery and recycle of the IL itself. Pervaporation (PV) is a highly selective and scalable membrane separation process for quantitatively recovering volatile solutes or solvents directly from non-volatile solvents that could prove more versatile for IL dehydration.

RESULTS

We evaluated a commercially available PV system for IL dehydration and recycling as part of an integrated IL pretreatment process using 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]) that has been proven to be very effective as a biomass pretreatment solvent. Separation factors as high as 1500 were observed. We demonstrate that >99.9 wt% [C₂C₁Im][OAc] can be recovered from aqueous solution (≤20 wt% IL) and recycled five times. A preliminary technoeconomic analysis validated the promising role of PV in improving overall biorefinery process economics, especially in the case where other IL recovery technologies might lead to significant losses.

CONCLUSIONS

These findings establish the foundation for further development of PV as an effective method of recovering and recycling ILs using a commercially viable process technology.

Double salt ionic liquids based on 1-ethyl-3-methylimidazolium acetate and hydroxyl-functionalized ammonium acetates: strong effects of weak interactions

The weaker N–H⋯O interactions between hydroxyl-functionalized ammonium acetates are more important than the stronger O–H⋯O interactions in determining solubility in the ionic liquid 1-ethyl-3-methylimidazolium acetate.

Separate mechanisms of ion oligomerization tune the physicochemical properties of n-butylammonium acetate: cation-base clusters vs. anion-acid dimers

Ions comprising protic ionic liquids strongly interact with their neutral acid and base forms as exemplified by n-butylammonium acetate in the presence of excess n-butylamine or acetic acid.

State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review

Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed.

Fingerprint of persistent organic pollutants in tissues of Antarctic notothenioid fish

In the present work, persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, polybrominated diphenyl ethers (PBDEs), and hexachlorocyclohexane (HCH) were analyzed in three Antarctic notothenioids fish species: Trematomus newnesi (TRN), Notothenia coriiceps (NOC) and Notothenia rossii (NOR). The contribution of each POP-family to the total load was as follows: ΣPCB (40%)>ΣDDT (27%)>ΣPBDEs (23%)>ΣHCH (10%). Among the 23 PCB congeners analyzed, penta-CBs homologues were the prevalent group, followed by hexa-CBs and hepta-CBs. DDT and its metabolites presented the following trend: p,p'-DDT>p,p'-DDE~p,p'-DDD. PBDE profile was dominated by BDE-47 and BDE-99 congeners, followed by BDE-100>BDE-28>BDE-154, BDE-153. Among HCHs, the γ-HCH isomer was detected in all samples, constituting 69% total HCH load, while α-HCH and β-HCH contributions were 15% and 16%, respectively. The levels of POPs reported here suggest that NOR and NOC are more susceptible to accumulate the analyzed contaminants than TRN, a species not previously analyzed for POPs. Distribution of POPs among different tissues of the three species (muscle, liver, gonads, and gills) was also investigated. Considering lipid weight, the general pattern of POPs distribution in tissues indicated that while gonads showed higher levels of PCBs, DDTs and HCH, the most significant PBDE concentrations were recorded in gills. Also, a comparative analysis of POPs concentration in fish samples from Antarctic area was included.

Ultrasound leaching-dispersive liquid-liquid microextraction based on solidification of floating organic droplet for determination of polybrominated diphenyl ethers in sediment samples by gas chromatography-tandem mass spectrometry

Ultrasound leaching-dispersive liquid-liquid microextraction using solidification of floating organic droplet (USL-DLLME-SFO) technique is proposed for extraction and isolation of polybrominated diphenyl ethers (PBDEs) from sediment and further determination by gas chromatography-tandem mass spectrometry (GC-MS/MS). Parameters that affect the efficiency of the procedure were investigated by a full factorial (2(k)) screening design. Variables showing significant effects on the analytical responses were considered within a further central composite design (CCD). The optimization assays have led to following protocol: ultrasound assisted lixiviation of 1g sediment was carried out by using 1.2 mL MeOH. Further, the analytes were isolated from 0.4 mL of the extract using the DLLME-SFO technique. The microextraction was performed using 0.1 mL MeOH, 22 mg 1-dodecanol, 1 mL NaCl solution 6.15M and 4.4 mL ultrapure water as dispersive and extracting solvents, medium ionic strength and dispersant bulk, respectively. Under optimum conditions, the method exhibits good performance in terms of linearity and precision (RSD<9.2%), with recoveries above 71% and limits of detection (LODs) within the range 0.5-1.8 pgg(-1) dry weight (d.w.). Method validation was demonstrated through the analysis of environmental sediment samples in which PBDEs were detected and quantified. The presence of BDE-47, -100, -99 and -153 was reported within the concentration range of <LOD to 29 pgg(-1) d.w. The proposed methodology constitutes a suitable approach for the analysis of PBDEs in complex solid samples requires minimum organic solvents consumption, sample manipulation, and increases sample throughput.

An online ionic liquid-based microextraction system coupled to electrothermal atomic absorption spectrometry for determination in environmental samples and pharmaceutical formulations

In the present work, an ionic liquid (IL) lighter than water was employed as extraction solvent in a dispersive liquid-liquid microextraction (DLLME) methodology. An original flow injection system for online microextraction and preconcentration of cobalt (Co) based on the use of tetradecyl(trihexyl)phosphonium chloride (CYPHOS® IL 101) was designed. Cobalt was complexed with 4-(2-pyridylazo)-resorcinol (PAR) reagent at pH 4.8 and then, the IL-DLLME procedure was developed by dispersing CYPHOS® IL 101 with acetone in an aqueous solution containing Co-PAR complex. Different pyridylazo dyes were evaluated for Co preconcentration in terms of their molecular structure, stability and acid-base equilibrium. Online extraction of Co-PAR into the IL and separation of the dispersed IL enriched phase were accomplished with a microcolumn containing Florisil material. Cobalt was removed from the microcolumn with a 10% (v/v) HNO3 acidified-acetone solution and finally measured by electrothermal atomic absorption spectrometry (ETAAS). The detection limit achieved after preconcentration of 2 mL of sample solution was 8 ng L-1. The precision for 10 replicate determinations at the 1 µg L-1 Co level was 5.1% relative standard deviation (RSD), calculated from the peak heights obtained. The method was successfully applied to Co determination in water samples as well as ophthalmic and parenteral solutions. For the first time, an IL-based microextraction technique was applied for metal determination in these complex samples, where Co recovery varied between 97.9 and 103%.

Development of an on-line temperature-assisted ionic liquid dispersive microextraction system for sensitive determination of vanadium in environmental and biological samples

An original flow injection (FI) system was developed for on-line microextraction of Vanadium (V) based on room temperature ionic liquid (RTIL). Vanadium was complexed with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) at pH 4.0. A 40 microL-volume of 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF(6)]) RTIL was mixed with 5 mL of sample solution containing the V-5-Br-PADAP complex. Then, a fully on-line temperature-assisted dispersion procedure was developed, followed by, analyte microextraction; and final on-line separation of the RTIL phase with a florisil-containing microcolumn. Vanadium was removed from the microcolumn with a 10% (v/v) nitric acid (in acetone) solution, and finally measured by electrothermal atomic absorption spectrometry (ETAAS). The detection limit achieved after preconcentration of 5 mL of sample solution, was 4.8 ng L(-1). The relative standard deviation (RSD) for 10 replicate determinations at 5 microg L(-1) of vanadium level was 4.1%, calculated from the obtained peak heights. The calibration graph was linear, with a correlation coefficient of 0.9982 at levels from the detection limits up to 15 microg L(-1). The method was successfully applied for the determination of vanadium in environmental and biological samples.