Measurement of ionized XXXX in serum with ion-selective electrodes: a mature technology that can meet the daily service needs.

@entity141 @entity1 @entity9506 @entity460
This article reviews key advances in ion-selective electrode technology that have made potentiometric measurements of ionized @entity460 ( @entity141 ) reliable and precise. Our use of two second-generation @entity141 analyzers (Radiometer @entity9506 and NOVA 8) made possible uninterrupted service as volume increased to 31 640 @entity1 tests in 1985. The lower results on the NOVA 8 were adjusted upwards to match those of the @entity9506 to give identical results. Both analyzers were evaluated under working conditions of high volumes and multiple operators to establish downtime, electrode life, and costs. We have classified all @entity141 analyzers into first-, intermediate-, and second-generation instruments, the better to understand their differences. Results for large numbers of @entity1 ' sera were shown to be systematically different when any two analyzers were compared. These differences are the consequence of each manufacturer's unique choices of the following: (a) the matrix of the @entity460 calibration solutions, (b) the type and configuration of the reference electrode, and (c) the salt-bridge solution. Elimination of each analyzer's biases will require agreement on a reference system that defines the accuracy of @entity141 measurements on serum, plasma, or whole blood. The sound analytical performance of today's second-generation @entity141 analyzers has allowed us to exploit the inherent superiority of @entity141 over total @entity460 (CaT) measurements in the daily care of @entity1 . We report on the preference of @entity141 over CaT by physicians at our hospital since the introduction of second-generation @entity141 analyzers. Therefore, we state unequivocally from our very satisfactory experience over the past five years that @entity141 is a clinical laboratory test whose time has come!
