Document Detail

Uncertainty of the sample size reduction step in pesticide residue analysis of large-sized crops.
MedLine Citation:
PMID:  23039817     Owner:  NLM     Status:  Publisher    
To estimate the uncertainty of the sample size reduction step, each unit in laboratory samples of papaya and cucumber was cut into four segments in longitudinal directions and two opposite segments were selected for further homogenisation while the other two were discarded. Jackfruit was cut into six segments in longitudinal directions, and all segments were kept for further analysis. To determine the pesticide residue concentrations in each segment, they were individually homogenised and analysed by chromatographic methods. One segment from each unit of the laboratory sample was drawn randomly to obtain 50 theoretical sub-samples with an MS Office Excel macro. The residue concentrations in a sub-sample were calculated from the weight of segments and the corresponding residue concentration. The coefficient of variation calculated from the residue concentrations of 50 sub-samples gave the relative uncertainty resulting from the sample size reduction step. The sample size reduction step, which is performed by selecting one longitudinal segment from each unit of the laboratory sample, resulted in relative uncertainties of 17% and 21% for field-treated jackfruits and cucumber, respectively, and 7% for post-harvest treated papaya. The results demonstrated that sample size reduction is an inevitable source of uncertainty in pesticide residue analysis of large-sized crops. The post-harvest treatment resulted in a lower variability because the dipping process leads to a more uniform residue concentration on the surface of the crops than does the foliar application of pesticides.
P Yolci Omeroglu; A Ambrus; D Boyacioglu; E Solymosne Majzik
Related Documents :
1810947 - Determination of neomycin in plasma and urine by high-performance liquid chromatography...
2577387 - The use of graphitized carbon black in solid phase extraction: comparison with c18 bond...
4086647 - Direct derivatization of alprenolol and its 4-hydroxy metabolite in urine with phosgene...
8593427 - Selective and sensitive determination of pamidronate in human plasma and urine by gas c...
15295887 - The modular analytical procedure and validation approach and the units of measurement f...
7410507 - Determination of residues of anabolic drugs in meat by gas chromatography-mass spectrom...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-10-8
Journal Detail:
Title:  Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment     Volume:  -     ISSN:  1944-0057     ISO Abbreviation:  Food Addit Contam Part A Chem Anal Control Expo Risk Assess     Publication Date:  2012 Oct 
Date Detail:
Created Date:  2012-10-8     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101485040     Medline TA:  Food Addit Contam Part A Chem Anal Control Expo Risk Assess     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
a Faculty of Engineering and Architecture, Food Engineering Department , Okan University , Akfirat-Tuzla-Istanbul , Turkey.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  3D Spirals with Controlled Chirality Fabricated Using Metal-Assisted Chemical Etching of Silicon.
Next Document:  Differential expression of TNFR1 (CD120a) and TNFR2 (CD120b) on subpopulations of human monocytes.