Impact of urine preservation methods and duration of storage on measured levels of environmental contaminants.
Author(s): Hoppin JA, Ulmer R, Calafat AM, Barr DB, Baker SV, Meltzer HM, Rønningen KS
Publication: J Expo Sci Environ Epidemiol, 2006, Vol. 16, Page 39-48
PubMed ID: 16007114 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to evaluate the effects of preservative, storage temperature, and storage duration on levels of environmental contaminants in spiked urine specimens.
Conclusion of Paper
The most significant impact on concentration of environmental contaminants was storage duration with storage of more than 72 h generally leading to reduced concentrations; however most concentrations changed by less than 20%. Generally storage temperature was not a significant contributor to change in analytes, but monoethyl phthalate (MEP) stored without preservative, monooctyl phthalate (MOP) preserved with boric acid, and phenolic metabolites were significantly affected by temperature. The use of preservatives significantly affected detection of dialkylphosphate (DAP) and phthalate metabolites stored at -20 degrees C. Bisphenol A (BPA) quantification was not significantly impacted by preservative or storage temperature.
Studies
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Study Purpose
The purpose of this study was to evaluate the effects of preservatives, storage temperature, and storage duration on levels of environmental contaminants in spiked urine specimens. Analytes included BPA, metabolites of organophosphate, carbamate, and pyrethroid insecticides, chlorinated phenols, and phthalate monoesters.
Summary of Findings:
The most significant impact on concentration of environmental contaminants was storage duration with storage of more than 72 h generally leading to reduced concentrations. The phthalates were particularly sensitive to storage duration and no longer detectable after 7 days, regardless of storage temperature and preservative. Most other concentration changes attributable to storage duration remained under 20%. Generally storage temperature was not a significant contributor to change in analytes, but MEP stored without preservative, MOP preserved with boric acid, and several phenolic metabolites were significantly affected by temperature. The presence of boric acid prevented detection of three DAP metabolites and resulted in significant changes in two others, indicating boric acid is not a suitable preservative to be used when measuring DAP metabolites. The use of chlorhexadine as a preservative also significantly impacted DAP quantification, particularly when storage was conducted at 4 degrees C, but effects were also observed at room temperature. Finally, preservative significantly impacted phthalate metabolites when spiked urine was stored at -20 degrees C. Notably, BPA quantification was not significantly impacted by preservative or storage temperature.
Biospecimens
Preservative Types
- None (Fresh)
- Other Preservative
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Small molecule GC-MS Small molecule HPLC-MS Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature Room temperature
4 degrees C
-20 degrees C
Storage Storage duration 0 h
24 h
48 h
72 h
1 week
Biospecimen Preservation Type of fixation/preservation Chlorhexadine
None (fresh)
Boric acid