Hi Esbena,
This may be a place to begin looking: (not mouse serum or urine, but maybe starting separations conditions--)
Journal of Chromatography B, Volume 879, Issues 5–6, 15 February 2011, Pages 429–435, Xinhua Dai, Xiang Fang,
Mingwu Shao, Ming Li, Zejian Huang, Hongmei Li, You Jiang, Dewei Song, Yajuan He. Certified reference materials (GBW09170 and 09171) of creatinine in human serum.
National Institute of Metrology, No. 18 Beisanhuan Donglu, Chaoyang Dist., Beijing 100013, PR China
Abstract
Creatinine is the most widely used clinical marker for assessing renal function. Concentrations of creatinine in human serum need to be carefully checked in order to ensure accurate diagnosis of renal function. Therefore, development of certified reference materials (CRMs) of creatinine in serum is of increasing importance. In this study, two new CRMs (Nos. GBW09170 and 09171) for creatinine in human serum have been developed. They were prepared with mixtures of several dozens of healthy people's and kidney disease patient's serum, respectively. The certified values of 8.10, 34.1 mg/kg for these two CRMs have been assigned by liquid chromatography–isotope dilution mass spectrometry (LC–IDMS) method which was validated by using standard reference material (SRM) of SRM909b (a reference material obtained from National Institute of Standards and Technology, NIST). The expanded uncertainties of certified values for low and high concentrations were estimated to be 1.2 and 1.1%, respectively. The certified values were further confirmed by an international intercomparison for the determination of creatinine in human serum (Consultative Committee for Amount of Substance, CCQM) of K80 (CCQM-K80). These new CRMs of creatinine in human serum pool are totally native without additional creatinine spiked for enrichment. These new CRMs are capable of validating routine clinical methods for ensuring accuracy, reliability and comparability of analytical results from different clinical laboratories. They can also be used for instrument validation, development of secondary reference materials, and evaluating the accuracy of high order clinical methods for the determination of creatinine in human serum.
Another potential reference(s):
Journal of Chromatography B, Volume 870, Issue 2, 15 July 2008, Pages 154–159, Determination of 3-hydroxyisovalerylcarnitine and other acylcarnitine levels using liquid chromatography–tandem mass spectrometry in serum and urine of a patient with multiple carboxylase deficiency.
Clin Chim Acta. 2011 Nov 20;412(23-24):2132-40. A metabolic profiling analysis of symptomatic gout in human serum and urine using high performance liquid chromatography-diode array detector technique.
Ann Pharmacother. 2006 May;40(5):900-8. Epub 2006 May 2. Estimation of creatinine clearance in end-stage liver disease.
