A non-chromatographic separation and preconcentration method for Se species determination based on the use of an on-line ionic liquid (IL) dispersive microextraction system coupled to electrothermal atomic absorption spectrometry (ETAAS) is proposed. Retention and separation of the IL phase was achieved with a Florisil(®)-packed microcolumn after dispersive liquid-liquid microextraction (DLLME) with tetradecyl(trihexyl)phosphonium chloride IL (CYPHOS(®) IL 101). Selenite [Se(IV)] species was selectively separated by forming Se-ammonium pyrrolidine dithiocarbamate (Se-APDC) complex followed by extraction with CYPHOS(®) IL 101. The methodology was highly selective towards Se(IV), while selenate [Se(VI)] was reduced and then indirectly determined. Several factors influencing the efficiency of the preconcentration technique, such as APDC concentration, sample volume, extractant phase volume, type of eluent, elution flow rate, etc., have been investigated in detail. The limit of detection (LOD) was 15 ng L(-1) and the relative standard deviation (RSD) for 10 replicates at 0.5 μg L(-1) Se concentration was 5.1%, calculated with peak heights. The calibration graph was linear and a correlation coefficient of 0.9993 was achieved. The method was successfully employed for Se speciation studies in garlic extracts and water samples.
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http://dx.doi.org/10.1016/j.talanta.2011.07.065 | DOI Listing |
Anal Chim Acta
November 2024
National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki, 305-8563, Japan. Electronic address:
Background: Aluminium is a mono-isotope element and can be determined by inductively coupled plasma mass spectrometry (ICP-MS). The measurement of aluminium by ICP-MS suffers potential spectral interferences from multiple elements, which make it challenging to ensure the reliability of the results. Fortunately, the availability of tandem quadrupole ICP-MS (i.
View Article and Find Full Text PDFMolecules
September 2024
School of Pharmacy, Shujitsu University, Nishigawara, Okayama 703-8516, Japan.
J Chromatogr A
October 2024
CNR-ISSMC- Institute of Science, Technology and Sustainability for Ceramics (ISSMC), Via Granarolo 64, I-48018, Faenza, RA, Italy. Electronic address:
J Chromatogr A
August 2024
Université Paris-Saclay, CNRS, Institut Galien Paris-Saclay 91400, Orsay, France. Electronic address:
This work explores strategies for electrokinetic preconcentration of extracellular vesicles (EVs) that are potential source of biomarkers for different diseases. The first approach that led to successful preconcentration of EVs is based on large volume sample stacking (LVSS), allowing an enrichment factor of 7 for CE of EVs with long-end injection (using a capillary with an effective length of 50 cm). Attempts were also made to perform multiple cycles of LVSS, field amplified sample stacking (FASS) and field amplified sample injection (FASI), to improve EVs preconcentration performance.
View Article and Find Full Text PDFJ Pharm Biomed Anal
September 2024
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China. Electronic address:
Metabolic dysregulation of catecholamines (CAs) is implicated in various human diseases. Simultaneously analyzing these acidic and alkaline CAs and their metabolites poses a significant challenge for clinical detection. This study introduces an efficient method employing automated online solid-phase extraction coupled with tandem mass spectrometry (aoSPE-MS/MS).
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