Ewald Usleber

Prof. Dr. Ewald Usleber

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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

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

Representative Publications

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23 May 2000 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
TVTerry Vrabcheva
Terry Vrabcheva
EUEwald Usleber
Ewald Usleber
RDRichard Dietrich
Richard Dietrich
EMErwin Märtlbauer
Erwin Märtlbauer

31 May 2008 in International Journal of Food Microbiology
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Journal Article
Closed access
ÖAÖmer Akineden
Ömer Akineden
AHAbdulwahed Ahmed Hassan
Abdulwahed Ahmed Hassan
ESElisabeth Schneider
Elisabeth Schneider
EUEwald Usleber
Ewald Usleber

23 May 2011 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
EUEwald Usleber
Ewald Usleber
VCValeriu Curtui
Valeriu Curtui
RDRichard Dietrich
Richard Dietrich
MGMadeleine Gross
Madeleine Gross
HLHadri Latif
Hadri Latif
EUEwald Usleber
Ewald Usleber

1 October 2004 in Toxicology Letters
Verified
Journal Article
Closed access
ESElisabeth Schneider
Elisabeth Schneider
VCValeriu Curtui
Valeriu Curtui
CSCaroline Seidler
Caroline Seidler
RDRichard Dietrich
Richard Dietrich
EUEwald Usleber
Ewald Usleber
EMErwin Märtlbauer
Erwin Märtlbauer

1 May 2016 in Food Control
Verified
Journal Article
Closed access
JBJulia I. Bauer
Julia I. Bauer
MGMadeleine Gross
Madeleine Gross
CGChristoph Gottschalk
Christoph Gottschalk
EUEwald Usleber
Ewald Usleber

1 January 1998 in The Analyst
Verified
Journal Article
Closed access
PDF file
WHWerner Heering
Werner Heering
EUEwald Usleber
Ewald Usleber
RDRichard Dietrich
Richard Dietrich
EMErwin Märtlbauer
Erwin Märtlbauer
Honey samples (n = 100; origin: various countries from Eurasia, Oceania, and the Americas) were analysed by enzyme immunoassays (EIA) for tetracyclines, streptomycin, and sulfathiazole. Considering antibody specificity, these EIAs are either quantitative (streptomycin) or qualitative (tetracyclines, sulfathiazole) tests. Honey extract purification was achieved by liquid–liquid partition (tetracyclines), and by solid phase extraction–immunoaffinity chromatography (streptomycin, sulfathiazole). Detection limits were 20 µg kg-1 (tetracycline equivalents), 10 µg kg–1 (streptomycin), and 50 µg kg–1 (sulfathiazole equivalents), with mean recoveries of 100–117%. A total of 42% of the samples was found positive by EIA; 25% were positive in one assay, 13% in two, and 3% were positive in all three tests. In the EIA for tetracyclines, 26% were positive, with 12 samples exceeding a level of 50 µg kg–1 (tetracycline equivalents). In the EIA for streptomycin, 19% were positive, with a mean concentration of 19 ± 12 µg kg–1. In the sulfathiazole EIA, 16% of the samples were positive, with 13 samples exceeding a level of 100 µg kg–1 (sulfathiazole equivalents). However, when samples which were positive in the sulfathiazole EIA were reanalysed for sulfonamides by HPLC, no sulfa drugs could be detected. Experimental heating (40 °C) of honey spiked with sulfathiazole indicated that the sulfa drug(s) responsible for positive EIA results could be present as sugar derivatives.