Solid supports and supported liquid membranes for different liquid phase microextraction and electromembrane extraction configurations. A review.

Liquid phase microextraction (LPME) and electromembrane microextraction (EME) can be considered as two of the most popular techniques in sample treatment today. Both techniques can be configurated as membrane-assisted techniques to carry out the extraction. These supports provide the required geometry and stability on the contact surface between two phases (donor and acceptor) and improve the reproducibility of sample treatment techniques. These solid support pore space, once is filled with organic solvents, act as a selective barrier acting as a supported liquid membrane (SLM). The SLM nature is a fundamental parameter, and its selection is critical to carry out successful extractions. There are numerous SLMs that have been successfully employed in a wide variety of application fields. The latter is due to the specificity of the selected organic solvents, which allows the extraction of compounds of a very different nature. In the last decade, solid supports and SLM have evolved towards "green" and environmentally friendly materials and solvents. In this review, solid supports implemented in LPME and EME will be discussed and summarized, as well as their applications. Moreover, the advances and modifications of the solid supports and the SLMs to improve the extraction efficiencies, recoveries and enrichment factors are discussed. Hollow fiber and flat membranes, including microfluidic systems, will be considered depending on the technique, configuration, or device used.

Native Chilean Berries Preservation and In Vitro Studies of a Polyphenol Highly Antioxidant Extract from Maqui as a Potential Agent against Inflammatory Diseases.

The best conservation method for native Chilean berries has been investigated in combination with an implemented large-scale extract of maqui berry, rich in total polyphenols and anthocyanin to be tested in intestinal epithelial and immune cells. The methanolic extract was obtained from lyophilized and analyzed maqui berries using Folin-Ciocalteu to quantify the total polyphenol content, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) to measure the antioxidant capacity. Determination of maqui's anthocyanins profile was performed by ultra-high-performance liquid chromatography (UHPLC-MS/MS). Viability, cytotoxicity, and percent oxidation in epithelial colon cells (HT-29) and macrophages cells (RAW 264.7) were evaluated. In conclusion, preservation studies confirmed that the maqui properties and composition in fresh or frozen conditions are preserved and a more efficient and convenient extraction methodology was achieved. In vitro studies of epithelial cells have shown that this extract has a powerful antioxidant strength exhibiting a dose-dependent behavior. When lipopolysaccharide (LPS)-macrophages were activated, noncytotoxic effects were observed, and a relationship between oxidative stress and inflammation response was demonstrated. The maqui extract along with 5-aminosalicylic acid (5-ASA) have a synergistic effect. All of the compiled data pointed out to the use of this extract as a potential nutraceutical agent with physiological benefits for the treatment of inflammatory bowel disease (IBD).

A novel approach for electromembrane extraction based on the use of silver nanometallic-decorated hollow fibers.

A novel approach based on the use of nanometallic-decorated hollow fibers to assist electromembrane extraction is proposed. Microporous polypropylene hollow fibers, on which nanometallic silver was deposited, have been used for the first time as liquid membrane support in electromembrane extraction (EME). Different methods for the generation/deposition of silver nanoparticles (AgNPs) were studied. The best results were obtained with chemical reduction of silver nitrate using NaBH4 in aqueous solution followed by direct deposition on the hollow fibers. The extraction performance of the new supports was compared with a previously developed EME procedure used for the extraction of selected non-steroidal anti-inflammatory drugs (NSAIDs), resulting in an increase in the extraction ratio by a factor of 1.2-2 with a 30% reduction in the extraction time. The new nanometallic-decorated supports open new possibilities for EME due to the singular properties of nanometallic particles, including chemical fiber functionalization.

Application of three phase hollow fiber based liquid phase microextraction (HF-LPME) for the simultaneous HPLC determination of phenol substituting compounds (alkyl-, chloro- and nitrophenols).

This work proposes for the first time the use of a three phase hollow fiber liquid phase microextraction (HF-LPME) procedure for the simultaneous extraction, and the later HPLC determination, of some phenol substituting compounds (alkyl-, chloro- and nitrophenols) that are considered as highly toxic compounds and/or endocrine disrupting ones. The substances studied include four chlorophenols (CPs): 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,6-dichlorophenol (2,6-DCP) and pentachlorophenol (PCP), three nitrophenols (NPs): 2,4-dinitrophenol (2,4-DNP), 2,5-dinitrophenol (2,5-DNP) and 2,6-dinitriphenol (2,6-DNP) and two alkylphenols (APs): tert butylphenol (TBP) and sec butylphenol (SBP). The extraction was carried out through a dihexyl ether liquid membrane supported on an Accurel(®) Q3/2 polypropylene hollow fiber. Optimum pH for donor and acceptor phases and extraction time were established. The enrichment (preconcentration) factors obtained were between 30 and 700 that allows detection limits between 140 and 290 pg mL(-1). The method was successfully applied to the determination of the compounds in environmental water samples, including urban wastewaters.

HPLC determination of ibuprofen, diclofenac and salicylic acid using hollow fiber-based liquid phase microextraction (HF-LPME).

This paper describes an extraction method using a polypropylene membrane supporting dihexyl ether (three-phase hollow fiber-based liquid phase microextraction (HF-LPME)) for the analysis of several pharmaceuticals (salicylic acid (SAC), ibuprofen (IBU) and diclofenac (DIC)) followed by a HPLC determination using a monolithic silica type HPLC column, that allows lower retention times than the usual packed columns with adequate resolution. Detection was realized by means of a coupled in series diode array (DAD) and fluorescence (FLD) detectors. HF-LPME is a relatively new technique employed in analytical chemistry for sample pretreatment which offers more selectivity and sensitivity than any traditional extraction technique. Detection limits by DAD are 12, 53 and 40 ng mL(-1) for salicylic acid, diclofenac and ibuprofen, respectively and by FLD 7 and 2 ng mL(-1) for salicylic acid, and ibuprofen. The method has been successfully applied to their direct determination in human urine and the results obtained demonstrated that could be also applied to the determination of the corresponding metabolites.

Mineral content and botanical origin of Spanish honeys.

Eleven elements (Zn, P, B, Mn, Mg, Cu, Ca, Ba, Sr, Na and K) were determined by inductively plasma coupled spectrometry in 40 honey samples from different places of Spain and four different botanical origins: Eucalyptus (Eucalyptus sp.), Heather (Erica sp.), Orange-blossom (Citrus sinensis) and Rosemary (Rosmarinus officinalis). K, Ca and P show the higher levels with average concentrations ranged between 434.1-1935mgkg(-1) for K; 42.59-341.0mgkg(-1) for Ca and 51.17-154.3mgkg(-1) for P. Levels of Cu (0.531-2.117mgkg(-1)), Ba (0.106-1.264mgkg(-1)) and Sr (0.257-1.462mgkg(-1)) are the lowest in all honey samples. Zn (1.332-7.825mgkg(-1)), Mn (0.133-9.471mgkg(-1)), Mg (13.26-74.38mgkg(-1)) and Na (11.69-218.5mgkg(-1)) concentrations were found strongly dependent on the kind of botanical origin. Results were submitted to pattern recognition procedures, unsupervised methods such as cluster and principal components analysis and supervised learning methods like linear discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Spanish honeys from different botanical origins according to their mineral content. Cluster analysis shows four clusters corresponding to the four botanical origins of honey and PCA explained 71% of the variance with the first two PC variables. The best-grouped honeys were those from heather; eucalyptus honeys formed a more dispersed group and finally orange-blossom and rosemary honeys formed a less distinguishable group.