Long-term stability of water samples— reanalysis of 20-year-old unpreserved samples

2019 ◽  
Vol 193 (2) ◽  
pp. 167-171
Author(s):  
Espen Enge
Keyword(s):  
Ambient Temperature ◽  
Water Samples ◽  
Water Bodies ◽  
Total Hardness ◽  
Term Stability ◽  
Long Term Stability ◽  
Long Term Storage ◽  
Stability Of Water ◽  
Term Storage

The current study compiles data from the reanalysis of 25 water samples stored unpreserved at ambient temperature for 20 years. Small changes in pH, conductivity and chloride and no significant effects on Al and total hardness were detected. The small effects measured, even during long-term storage under unsuitable conditions, suggest that samples taken from pristine water bodies remain chemically stable over many years.

scholarly journals Instability of corticotropin during long-term storage – myth or reality?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jacquelien J. Hillebrand ◽  
Li Zhou ◽  
Marilee A. Marcinkus ◽  
Maria Datwyler ◽  
Susan H. Gawel ◽  
...  
Keyword(s):  
Storage Time ◽  
Storage Temperature ◽  
Ethylenediaminetetraacetic Acid ◽  
Venous Blood ◽  
Sampling Studies ◽  
Term Stability ◽  
Long Term Stability ◽  
Long Term Storage ◽  
Term Storage

Abstract Objectives Corticotropin is notorious for its instability. Whereas several studies have investigated its short-term stability in plasma following venous blood sampling, studies on long-term stability are lacking. Here we investigated the long-term storage stability of corticotropin in ethylenediaminetetraacetic acid containing plasma. Methods Specimens from healthy volunteers (neat, spiked) were stored in polypropylene microcentrifuge tubes with socket screw-caps at −20 °C and −70 °C for up to one and a half years. Corticotropin in plasma was measured using an Abbott research only immunoassay. Separately, specimens from patients were collected during diagnostic routine testing and stored in polystyrene tubes with push-caps at −20 °C for up to 6 years. In these samples corticotropin hormone was measured using the Diasorin corticotropin immunoassay. Results Storage of specimens at −20 °C or −70 °C for up to one and a half years showed minimal changes (<11%) in corticotropin levels, while storage of patient samples at −20 °C for up to 6 years showed a significant (54%) reduction in corticotropin levels. Conclusions Corticotropin levels are stable in plasma when stored at −20 °C for one and a half years using the Abbott research only assay, but with longer storage time a significant reduction in corticotropin levels can be expected. Once specimens are stored for future corticotropin measurements, one should consider storage time, storage temperature and assay differences.

The Long-Term Stability in Whole Blood of 14 Commonly-Requested Hormone Analytes

1994 ◽  
Vol 31 (6) ◽  
pp. 561-565 ◽  
Author(s):  
M J Diver ◽  
J G Hughes ◽  
J L Hutton ◽  
C R West ◽  
L J Hipkin
Keyword(s):  
Ambient Temperature ◽  
Whole Blood ◽  
Great Majority ◽  
Red Cells ◽  
Clinical Interpretation ◽  
Term Stability ◽  
Long Term Stability ◽  
Plasma Hormones

Concentrations of 14 commonly-requested plasma hormones were measured in octuplicate in each of six subjects to determine their stability when unseparated from red cells for periods up to 1 week. Most of the analytes were stable when stored in this way and although statistically significant changes were recorded, in the great majority of cases the changes seen would have no bearing on the clinical interpretation of the result. In the light of these findings, we would confidently report results of analyses for these hormones in plasma that had remained in contact with red cells at ambient temperature for long periods of time.

Effects of Tween 80 and Sucrose on Acute Short-Term Stability and Long-Term Storage at −20 C of a Recombinant Hemoglobin

1998 ◽  
Vol 87 (9) ◽  
pp. 1062-1068 ◽  
Author(s):  
Bruce A. Kerwin ◽  
Martin C. Heller ◽  
Steven H. Levin ◽  
Theodore W. Randolph
Keyword(s):  
Tween 80 ◽  
Short Term ◽  
Term Stability ◽  
Long Term Storage ◽  
Term Storage

Long-term storage of somatic embryogenic white spruce tissue at ambient temperature

1991 ◽  
Vol 25 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Richard W. Joy ◽  
Prakash P. Kumar ◽  
Trevor A. Thorpe
Keyword(s):  
Ambient Temperature ◽  
White Spruce ◽  
Long Term Storage ◽  
Somatic Embryogenic ◽  
Term Storage

A Versatile Temperature-Controlled Reaction Cuvet

1975 ◽  
Vol 21 (8) ◽  
pp. 1175-1178
Author(s):  
Michael G Busby ◽  
David B Cottrell ◽  
George S Cembrowski ◽  
E Clifford Toren
Keyword(s):  
Ambient Temperature ◽  
Temperature Control ◽  
Recovery Time ◽  
Visible Region ◽  
Term Stability ◽  
Long Term Stability ◽  
Temperature Recovery ◽  
Temperature Controlled

Abstract A thermostatted reaction cuvet, operating under computerized or manual temperature control in the ultraviolet or visible region, is described and evaluated. The cell was designed for use with the automated chemistry system described earlier [Clin. Chem. 19, 1114 (1973)], but can readily be adapted for other applications. The entire 3-ml cuvet assembly warms from ambient temperature to 37 °C in less than 10 min, with ±0.15 °C stability; the long-term stability is ±0.05 °C; temperature recovery time after washing or reagent addition is less than 3 min. The optical pathlength is 10.00 mm and the carryover volume is 18 µl.

Speciation of Inorganic Arsenic and Selenium in Contaminated Ground Water Samples—Distribution and Long-Term Stability of Species

1998 ◽  
Vol 72 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Michael Rássler ◽  
Bernhard Michalke ◽  
Peter Schramel ◽  
Sigurd Schulte-hostede ◽  
Antonius Kettrup
Keyword(s):  
Ground Water ◽  
Water Samples ◽  
Inorganic Arsenic ◽  
Term Stability ◽  
Long Term Stability

scholarly journals Long-Term Stability of 18 Nutritional Biomarkers Stored at −20 °C and 5 °C for up to 12 Months

2018 ◽  
Vol 3 (1) ◽  
pp. 100-108
Author(s):  
Huiping Chen ◽  
Maya R Sternberg ◽  
Rosemary L Schleicher ◽  
Christine M Pfeiffer
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Iron Status ◽  
Geometric Mean ◽  
Water Soluble ◽  
Reference Condition ◽  
Term Stability ◽  
Long Term Stability ◽  
Long Term Storage

Abstract Background Consistent information on long-term storage stability for a broad range of nutritional biomarkers is lacking. We investigated the stability of 18 biomarkers stored at suboptimal temperatures (−20 °C and 5 °C) for up to 12 months. Methods Multiple vials of serum or whole blood pools (3 concentrations) were stored at −20 °C or 5 °C, removed from the −20 °C freezer after 3, 6, 9, and 12 months and from the 5 °C refrigerator after 6 and 12 months, and placed into a −70 °C freezer until analysis at study completion. Vials stored continuously at −70 °C were used as the reference condition for optimal storage. We measured 18 biomarkers: 4 iron status, 1 inflammation, 8 water-soluble vitamin, and 5 fat-soluble vitamin. For each temperature, we calculated geometric mean concentrations and average percent changes of geometric means across pools relative to the reference condition estimated from a linear mixed model. Results Most biomarkers (13 of 18) showed no difference in concentration after 12 months of storage at −20 °C. Serum ferritin (1.5%), soluble transferrin receptor (−1.7%), and folate (−10.5%) showed small to moderate significant changes at 6 months, but changes were acceptable based on biologic variability. Serum pyridoxal-5′-phosphate (−18.6% at 9 months) and vitamin C (−23% at 6 months) showed large and unacceptable changes at −20 °C. All serum fat-soluble vitamins and iron status indicators, vitamin B12, total homocysteine, and methylmalonic acid showed acceptable changes when stored at 5 °C for up to 12 months. Conclusions Overall, we found good long-term stability for multiple nutritional biomarkers stored at suboptimal temperatures.

scholarly journals Long-Term Stability of the Electronic Sensor Component of a Digital Pill System in Real-World Storage Settings

2021 ◽  
pp. 875512252098521
Author(s):  
Peter R. Chai ◽  
Georgia Goodman ◽  
Majo J. Bustamante ◽  
Yassir Mohamed ◽  
Jose Castillo-Mancilla ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Once Daily ◽  
Long Term Stability ◽  
Long Term Storage ◽  
System Requirements ◽  
The Stability ◽  
Term Storage

Background: Digital pill systems comprise an ingestible sensor integrated into a gelatin capsule that overencapsulates medication allowing real-time measures of medication ingestion. These systems may improve the manner in which medication adherence can be assessed and supported. Objective: In this investigation, we tested the durability of the ingestible sensor as part of a clinical trial to measure the feasibility and acceptability of the system to measure adherence to once daily tenofovir disoproxil fumarate/emtricitabine (NCT03842436). Methods: Digital pills not dispensed during the study were stored in a pharmacy. Seventeen sensors were selected from digital pills stored for at least 12 months and activated in a simulated gastric environment. A radiofrequency spectrum analyzer and the reader device used in the clinical trial to capture ingestion events were used to measure activation of emitters. A passing evaluation was defined as an energized emitter within 30 minutes of immersion, ability to broadcast a signal for 10 minutes, and successful acquisition by the reader. Results: All ingestible sensors passed the stability test. Mean activation time in simulated gastric fluid was 3.33 minutes (SD = 1.47); emitters remained active for a mean of 47.72 minutes (SD = 1.78). These parameters matched guidelines defined in the ID-Cap system requirements for use in patients. Conclusions: Ingestible sensor components of the ID-Cap system were therefore stable after long-term storage.

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