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Determination of ppb-level phenol index using in-syringe dispersive liquid-liquid microextraction and liquid waveguide capillary cell spectrophotometry
journal contribution
posted on 2023-05-19, 20:36 authored by Horstkotte, B, Fernando Maya AlejandroFernando Maya Alejandro, Duarte, CM, Cerda, VWe report on an in-syringe dispersive liquid-liquid microextraction (DLLME) technique and its application to the determination of the total phenol index in natural waters. Xylene was used as extraction solvent in combination with a mixture of acetonitrile and n-propanol as dispersion solvents. The analytical procedure consists of mixing the sample with buffer, reacting it with 4-aminoantipyrine and potassium hexacyanoferrate, DLLME, phase separation, and index quantification and was automated using the multisyringe flow injection analysis technique and takes 200 s only. DLLME was accomplished by aspiration of the mixture of extraction and dispersion solvents followed by the aqueous phases into the syringe at a high flow rate. Phase separation occurs due to aggregation of the floating extractant droplets (with their lower specific density) at the head of the syringe. The extractant containing the chromogenic reaction product is then pushed into an optical waveguide capillary cell and spectrophotometrically detected at 500 nm. Figures of merits include a low limit of detection (0.9 ppb), a preconcentration factor of 20, a linear dynamic range up to 140 ppb, and a general standard deviation of 3.1 %. The method enabled the concentration of phenols in well water samples to be determined with a mean recovery of 101 %.
History
Publication title
Microchimica ActaVolume
179Issue
1-2Pagination
91-98ISSN
0026-3672Department/School
School of Natural SciencesPublisher
Springer WienPlace of publication
AustriaRights statement
Copyright 2012 Springer-VerlagRepository Status
- Restricted