title: Do only small uremic toxins, chromophores, contribute to the online dialysis dose monitoring by UV absorbance?
abstract: The aim of this work was to evaluate the contributions of the main chromophores to the total UV absorbance of the spent dialysate and to assess removal dynamics of these solutes during optical on-line dialysis dose monitoring. High performance chromatography was used to separate and quantify UV-absorbing solutes in the spent dialysate sampled at the start and at the end of dialysis sessions. Chromatograms were monitored at 210, 254 and 280 nm routinely and full absorption spectra were registered between 200 and 400 nm. Nearly 95% of UV absorbance originates from solutes with high removal ratio, such as uric acid. The contributions of different solute groups vary at different wavelengths and there are dynamical changes in contributions during the single dialysis session. However, large standard deviation of the average contribution values within a series of sessions indicates remarkable differences between individual treatments. A noteworthy contribution of Paracetamol and its metabolites to the total UV absorbance was determined at all three wavelengths. Contribution of slowly dialyzed uremic solutes, such as indoxyl sulfate, was negligible.
authors.affiliation: Department of Biomedical Engineering, Technomedicum, Tallinn University of Technology, Tallinn, Estonia. jurgen.arund@ttu.ee
authors.forename: Jürgen
authors.initials: J
authors.lastname: Arund
authors.forename: Risto
authors.initials: R
authors.lastname: Tanner
authors.forename: Fredrik
authors.initials: F
authors.lastname: Uhlin
authors.forename: Ivo
authors.initials: I
authors.lastname: Fridolin
mesh_terms: D000042:Absorption; D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D015314:Dialysis Solutions / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007200:Indican / Q000097:blood; D008297:Male; D008991:Monitoring, Physiologic; D006435:Renal Dialysis; D014466:Ultraviolet Rays; D014511:Uremia / Q000097:blood / Q000628:therapy; D014527:Uric Acid / Q000097:blood
chemical_list: D015314:Dialysis Solutions; D014527:Uric Acid; D007200:Indican