Development of an online citrate/Ca2+ sensing system for dialysis.
An online citrate and Ca(2+) sensing system based on sequential injection analysis (SIA) is developed as a safety module for hemodialysis. Host 1 displays high affinity towards citrate, and was selected for this study owing to its unique structural features. The o-aminomethylphenylboronic moiety can effectively interact with the α-hydroxycarboxylate moiety of citrate and the remaining two guanidiniums may further stabilize the complex via hydrogen bonds. Fura-2 chelates to Ca(2+) with a high selectivity and affinity and was utilized in this study for Ca(2+) measurements. The citrate sensing chemistry via an indicator displacement assay is orthogonal to the Ca(2+) sensing chemistry, and the use of sophisticated chemometrics is not required for data analysis. The citrate and Ca(2+) concentrations in dialysate samples are measured with the developed SIA system. The obtained citrate concentrations were verified via a commercially available enzymatic assay and an NMR method, respectively, while the Ca(2+) concentrations were verified via atomic absorption.
Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA.
Youjun
Y
Yang
Balazs
B
Szamosfalvi
Jerry
J
Yee
Stanley
S
Frinak
Eric V
EV
Anslyn
D002118:Calcium / Q000032:analysis*; D019343:Citric Acid / Q000032:analysis*; D004867:Equipment Design; D004868:Equipment Failure; D017022:Flow Injection Analysis / Q000295:instrumentation; D015312:Hemodialysis Solutions / Q000737:chemistry*; D006435:Renal Dialysis / Q000295:instrumentation*; D013053:Spectrophotometry
D015312:Hemodialysis Solutions; D019343:Citric Acid; D002118:Calcium