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- Sandahl, Margareta, et al.
(författare)
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Automated determination of Vinclozolin at the ppb level in aqueous samples by a combination of microporous membrane liquid-liquid extraction and adsorption chromatography
- 2000
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Ingår i: Analytica Chimica Acta. - 1873-4324. ; 424:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- An automated system with microporous membrane liquid-liquid extraction (MMLLE) combined with HPLC has been designed for the determination of Vinclozolin in aqueous matrices. In MMLLE a porous hydrophobic membrane separates an aqueous phase from an organic phase. The pores are filled with the organic solvent. In this work, MMLLE was performed in a flow system and coupled on-line to normal phase HPLC. The performance of the system was evaluated with respect to enrichment when processing large sample volumes. Enrichment factors of 118 times were obtained and the limit of detection was around 1 ng/ml. This technique is an alternative to classical LLE and offers advantages such as reduced solvent consumption, possibility of automation and avoidance of emulsion formations. (C) 2000 Elsevier Science B.V.
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| 2. |
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| 3. |
- Sandahl, Margareta, et al.
(författare)
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On-line automated sample preparation for liquid chromatography using parallel supported liquid membrane extraction and microporous membrane liquid-liquid extraction
- 2002
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Ingår i: Journal of Chromatography A. - 0021-9673. ; 975:1, s. 211-217
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Tidskriftsartikel (refereegranskat)abstract
- An automated system was developed for analysis of non-polar and polar ionisable compounds at trace levels in natural water. Sample work-up was performed in a flow system using two parallel membrane extraction units. This system was connected on-line to a reversed-phase HPLC system for final determination. One of the membrane units was used for supported liquid membrane (SLM) extraction, which is suitable for ionisable or permanently charged compounds. The other unit was used for microporous membrane liquid-liquid extraction (MMLLE) suitable for uncharged compounds. The fungicide thiophanate methyl and its polar metabolites carbendazim and 2-aminobenzimidazole were used as model compounds. The whole system was controlled by means of four syringe pumps. While extracting one part of the sample using the SLM technique, the extract from the MMLLE extraction was analysed and vice versa. This gave a total analysis time of 63 min for each sample resulting in a sample throughput of 22 samples per 24 h. (C) 2002 Elsevier Science B.V. All rights reserved.
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