247
Views
1
CrossRef citations to date
0
Altmetric
Original Articles

Serum and urine osmolality: 8 hours, 24 hours and 1-month sample stability

, , , , , & show all
Pages 283-289 | Received 29 Dec 2021, Accepted 15 May 2022, Published online: 02 Jun 2022
 

Abstract

Objectives

The body of literature varies significantly regarding serum and urine osmolality stability. Therefore, our aim was to investigate the stability of serum and urine osmolality at different temperatures (room temperature (RT) 4–8 °C, −20 °C) and time conditions (8 h, 24 h, 1 month).

Methods

The stability study was conducted following the CRESS guidelines, including 40 serum and urine samples. Samples were aliquoted into three aliquots and stored as follows: primary tube stored at RT for 8 h; two capped aliquots stored at 4–8 °C for 8 h and 24 h; one aliquot stored at −20 °C for 1 month. To minimize imprecision error, serum and urine osmolality were measured by the freezing point depression method in triplicate on OSMOMAT 3000 (Gonotech, Germany) analyzer. Percentage difference (PD%) against baseline measurement was calculated. Deviations were assessed against a reference change value of 5.0%.

Results

The PD% for serum and urine osmolality was below 2.0% for all time/temperature conditions. For serum samples: primary tube after 8 h at RT PD% (95% CI) = 0.0% (−0.3, 0.2%); 8 h at 4–8 °C PD% (95% CI) = −0.4% (−0.7, 0.0%); 24 h at 4–8 °C PD% (95% CI) = −0.7% (−0.7, −0.6%); 1 month at −20 °C PD% (95% CI) = −2.1% (−2.4, −1.5%). For urine samples: after 8 h at RT PD% (95% CI) =0.6% (0.2, 0.9%); 8 h at 4–8 °C PD% (95% CI) = −0.2% (−0.5, 0.1%); 24 h at 4–8 °C PD% (95% CI) = −0.2% (−0.5, 0.0%); 1 month at −20 °C PD% (95% CI) = −2.0% (−3.0, −1.0%).

Conclusions

Changes in osmolality for tested conditions for serum and urine samples, were within acceptance criteria. Reflex and add-on osmolality testing can be performed within the same day in samples kept at RT for 8 h in primary tube and within 24 h, in aliquoted refrigerated samples, without compromising the reliability of test results. For longer storage, samples should be kept at −20 °C.

Ethical approval

Research involving human subjects complied with all relevant national regulations, institutional policies and is in accordance with the tenets of the Helsinki Declaration (as revised in 2013), and has been approved by the authors’ Institutional Ethical committee (02/1-91/95-2019).

Disclosure statement

The authors report there are no competing interests to declare.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 65.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 200.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.