This communication describes a new optical sensor suitable for practical measurement of extracellular (serum or whole blood) potassium. The sensor responds rapidly and reversibly to changes in potassium concentrations typical of whole blood samples. No interferences from clinical concentrations of calcium or pH are observed, and the sodium interference is very minor. Excitation and emission occur in the visible light region. This new potassium sensor is currently used in the Roche OPTI CCA, a commercially available whole blood analyzer.

A new optical sensor suitable for practical measurement of sodium in serum and whole blood samples is described. The optical sensor is based on a novel PET (photoinduced electron transfer) fluoroionophore immobilized in a hydrophilic polymer layer. The design concept of the fluoroionophore follows the receptor-spacer-fluorophore approach to sensor design using intramolecular PET-based signal transduction. Key to the development of this sensor is the identification of a nitrogen-containing, sodium-binding ionophore, coupled with a fluorophore having the correct spectral and electron-accepting properties. The slope of the sensor is approximately 0.5%/mM in the typical clinically significant range of 120-160 mM. This sensor has been implemented into a disposable cartridge, used for a commercially available critical care analyzer (Roche OPTI CCA) with precision better than +/- 1 mM (1 SD). The sensor displays excellent stability against hydrolysis and oxidation, leading to slope changes <5% after 9 months wet storage at 30 degrees C. On the basis of this design concept, fluoroionophores for other cations such as potassium, calcium and magnesium can be prepared by substitution of the ionophore.

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Synthese von 1: Methyldiphenylphosphanoxid (0.54 g. 2.5 mmolj und Lithiumbis-(trimethylsily1)amid (0.42 g, 2.5 mmol) wurden in kaltem Hexan/Toluol ( 5 mL/ 5 mL) aufgenommen. Nach kurrein Erwirmen der weil3en Suspension bildet sich eiiie hellgelbe Losung, aus der nach Abkiihlen ( 5 'C, 2 d) 1 in Form farbloser Blocke kristallisiert. Rohausbeute: 0.68 g, 71 %; Schmp. 148-152'C; korrekte Elementaranalyse fur C,,H,,LiNOPSi,; 'H-NMR (C,D,, 250 MHz, 25°C): 6 =7.58 (m, 4Hj, 7.09 (m, 6H). 1.62 (d, J=13.2Hz, 3H, Ph,P(O)CH,), 0.56 (s, IXH, LiN[Si(CH,),],). Eingegangen am 25. Januar 1996 [Z 87531 Stichworte: Ab-initio-Rechnungen -Amide * Festkorperstrukturen Lithiumverbindungen * Phosphorverbindungen [I] a) B.

Methods are reported for the attachment of -nucleophiles to the primary and secondary sides of the cyclodextrin cavity. Six new materials have been prepared in which /3CD has been modified by hydrazine, hydroxylamine, oxime, and hydroperoxide functionalities. Transacylating studies with p-NPA have demonstrated that the primary-side hydroxylamine shows the highest reactivity with a 1900-fold increase in rate over /3CD at pH 6.5. Other -nucleophiles show less remarkable rate increases in this system but, in some cases, demonstrate hydrogenbonding to the cyclodextrin rim and inhibition kinetics.