title: Infrared transmission spectrometry for the determination of urea in microliter sample volumes of blood plasma dialysates.
abstract: Application of mid-infrared spectroscopy for the determination of urea in blood plasma dialysates of microliter sample volumes using a transmission microcell was investigated. Infrared spectra of the dialysates of plasma samples collected from 75 different patients using CMA 60 microdialysis catheters were evaluated with multivariate partial least squares regression. Using the absorbance spectral data from 1520-1420 cm(-1) and 1220-1120 cm(-1), a minimum standard error of prediction (SEP) of 0.88 mg/dL (0.14 mM) was achieved with spectral variable selection. Our findings suggest the feasibility of developing a mid-infrared sensor in combination with micro-fluidics for on-line monitoring of urea in patients undergoing dialysis treatment.
authors.affiliation: ISAS-Institute for Analytical Sciences at the University of Dortmund, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany.
authors.forename: Venkata Radhakrishna
authors.initials: VR
authors.lastname: Kondepati
authors.forename: Uwe
authors.initials: U
authors.lastname: Damm
authors.forename: H Michael
authors.initials: HM
authors.lastname: Heise
mesh_terms: D015415:Biomarkers; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D016018:Least-Squares Analysis; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D006435:Renal Dialysis; D013055:Spectrophotometry, Infrared / Q000295:instrumentation* / Q000379:methods*; D014508:Urea / Q000097:blood*
chemical_list: D015415:Biomarkers; D014508:Urea