Urine-creatinine concentration as a marker of urine dilution: Reflections using a cohort of 45,000 samples

Arndt, T.

doi:10.1016/j.forsciint.2009.01.010

Cited by 77 publications

(45 citation statements)

References 5 publications

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“…The dilution procedure was optimized to yield linear detector response over the whole calibration range from 0.25 to 40 mmol/l (fig. 4), covering the full range of physiologically observed creatinine concentrations in human urine [39,40]. The lowest creatinine concentration measured in 270 urine samples was 0.8 mmol/l, so the lowest point of the calibration curve of 0.25 mmol/l was deemed properly selected.…”

Section: Discussionmentioning

confidence: 99%

Determination of Creatinine in Human Urine with Flow Injection Tandem Mass Spectrometry

Niesser

Koletzko²,

Peißner³

2012

Ann Nutr Metab

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Background/Aims: Excretion of urinary compounds in spot urine is often estimated relative to creatinine. For the growing number of liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays of urine-excreted molecules, a fast and accurate method for determination of creatinine is needed. Methods: A high-throughput flow injection tandem mass spectrometry method for exact quantitation of creatinine in urine has been developed and validated. Sample preparation used only two-step dilution for protein precipitation and matrix dilution. Flow injection analysis without chromatographic separation allowed for total run times of 1 min per sample. Creatinine concentrations were quantitated using stable isotope dilution tandem mass spectrometry. Selectivity and coelution-free quantitation were assured by qualifier ion monitoring. Results: Method validation revealed excellent injection repeatability of 1.0% coefficient of variation (CV), intraday precision of 1.2% CV and interday precision of 2.4% CV. Accuracy determined from standard addition experiments was 106.1 ± 3.8%. The linear calibration range was adapted to physiological creatinine concentrations. Comparison of quantitation results with a routinely used method (Jaffé colorimetric assay) proved high agreement (R² = 0.9102). Conclusions: The new method is a valuable addition to the toolbox of LC-MS/MS laboratories where excretion of urinary compounds is studied. The ‘dilute and shoot’ approach to isotope dilution tandem mass spectrometry makes the new method highly accurate as well as cost- and time-efficient.

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Section: Discussionmentioning

confidence: 99%

Determination of Creatinine in Human Urine with Flow Injection Tandem Mass Spectrometry

Niesser

Koletzko²,

Peißner³

2012

Ann Nutr Metab

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“…In general, these patients are treated in hospitals and not in settings investigated in this study. However, extremely high concentrations of creatinine in urine (up to7698mg/L in women and 8886mg/L in men) have been published in other studies that comparatively analysed approximately 45,000 urine samples from clinical chemistry and from toxicological chemistry laboratories [16]. As the samples were completely anonymized there was no need of any Institution Ethics Review Board for human studies.…”

Section: Urine Samples and Ethical Issuesmentioning

confidence: 99%

False Negative Results in Testing for Drugs of Abuse from Diluted Urine

2017

International Journal of Clinical Chemistry and Laboratory Medi

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“…Lower limit of detection for EtS: 0.01 mg/L. Spot urine-creatinine, used as a marker of in-vitro or in-vivo urine dilution [8] and for the calculation of EtG/creatinine ratios, was determined on a Hitachi 912 analyzer (Roche, Mannheim, Germany) using a modification of the Jaffe method (testkit by Thermo Fisher Scientific Microgenics).…”

Section: Etg and Ets Lc-ms/ms Confirmation Analysismentioning

confidence: 99%

False-positive ethyl glucuronide immunoassay screening associated with chloral hydrate medication as confirmed by LC–MS/MS and self-medication

Arndt¹,

Gierten²,

Güssregen³

et al. 2009

Forensic Science International

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Urine-creatinine concentration as a marker of urine dilution: Reflections using a cohort of 45,000 samples

Cited by 77 publications

References 5 publications

Determination of Creatinine in Human Urine with Flow Injection Tandem Mass Spectrometry

Determination of Creatinine in Human Urine with Flow Injection Tandem Mass Spectrometry

False Negative Results in Testing for Drugs of Abuse from Diluted Urine

False-positive ethyl glucuronide immunoassay screening associated with chloral hydrate medication as confirmed by LC–MS/MS and self-medication

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