Moisés Knochen

Prof. Moisés Knochen


Research Focus & Metrics

Academic Career Length

40Years (1987-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2003 in Journal of Pharmaceutical and Biomedical Analysis
Verified
Journal Article
Closed access
MKMoisés Knochen
Moisés Knochen
JGJavier Giglio
Javier Giglio
BRBoaventura F Reis
Boaventura F Reis

1 September 2019 in Journal of Food Composition and Analysis
Verified
Journal Article
Closed access
ASAlexandra Sixto
Alexandra Sixto
AMAlicia Mollo
Alicia Mollo
MKMoisés Knochen
Moisés Knochen

4 November 2015 in Journal of Analytical Atomic Spectrometry
Verified
Journal Article
Open access
PDF file
ASAlexandra Sixto
Alexandra Sixto
MFMarta Fiedoruk-Pogrebniak
Marta Fiedoruk-Pogrebniak
MRMaría Rosende
María Rosende
DCDavid J. Cocovi-Solberg
David J. Cocovi-Solberg
MKMoisés Knochen
Moisés Knochen
MMManuel Miró
Manuel Miró
An automatic programmable-flow system capitalizing upon mesofluidic Lab-On-Valve (LOV) sample processing coupled on-line to inductively coupled plasma atomic emission spectrometry (ICP-AES) is proposed in this work as a quality control tool for expedient assessment of potential contamination episodes of food safety elements (namely, Cd and Pb) in a variety of undigested ripened honeys, taken as a model of an edible matrix. On-chip micro-solid phase extraction (μSPE) is effected in a bead-injection disposable sorbent mode using a cationic exchange restricted access-like material (viz., Bond Elut Plexa PCX). We have proven that the lifetime of the miniaturized solid reactor on-chip (11 ± 0.6 mg) is limited to processing less than 6 mL of unfiltered sample suspension (5% (w/w) honey buffered at pH 4.5) after which the analytical performance is severely deteriorated because of strong adherence of the sample matrix to the bead surface. Several physicochemical parameters including the nature of the sorbent material and its ionic form were investigated in detail so as to maximize absolute recoveries and enrichment factors of Pb and Cd. Variables for the elution process were explored by means of a full factorial design. Using 4.0 mL of sample and 200 μL of 3.0 mol L−1 HNO3 as an eluent, enrichment factors of ca. 15 with extraction/elution efficiencies close to 80% and relative recoveries ranging from 90–111% in honey were obtained for both Pb and Cd. The limits of detection (LODs), based on the 3sintercept criterion, were 26 ng g−1 and 68 ng g−1 for Cd and Pb, respectively, which are far below those endorsed by current regulatory agencies (namely, 100 and 300–500 ng g−1 for Cd and Pb, respectively). Demonstrated by the analysis of a suite of off-the-shelf honey brands, the proposed LOV-μSPE platform hyphenated to ICP-AES is deemed suitable for the reliable quantitation of trace level concentrations of Pb and Cd in honey and the detection of heavy metal contamination episodes.


1 October 2015 in Talanta
Verified
Journal Article
Closed access
PGPablo González
Pablo González
MKMoisés Knochen
Moisés Knochen
MSMilton K. Sasaki
Milton K. Sasaki
EZElias Ayres Guidetti Zagatto
Elias Ayres Guidetti Zagatto

1 October 2011 in Environmental Geochemistry and Health
Verified
Journal Article
Closed access
PDF file
MPMariela Pistón
Mariela Pistón
JSJavier Silva
Javier Silva
RPRamiro Pérez-Zambra
Ramiro Pérez-Zambra
IDIsabel Dol
Isabel Dol
MKMoisés Knochen
Moisés Knochen