Performance of the Hitachi 705 Evaluated.

Abstract

We evaluated a new discrete analyzer, the Hitachi 705. The instrument can process sequentially as many as 19 different enzymes or other analytes, with a throughput of 180 tests per hour. We evaluated the spectrophotometer, the sample and reagent probes, and the performance for 11 assays: creatine kinase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransférase, amylase, glucose, urea nitrogen, creatinine, albumin, calcium, and phosphorus. The total imprecisions (within-day plus day-to-day component of imprecision) (CV) were: for the photometer (six concentrations of potassium dichromate), 0.14 to 0.4%; for the serum probe (55 to 20 microL), 0.4 to 1.0%; for the reagents probes (50 to 350 microL), 0.3 to 1.2%; for the enzymatic procedures, 2.0 to 8.0%; and for the other tests (glucose, urea nitrogen, creatinine), 1.0 to 4.0%. Good linearity was obtained in the proposed range for the 11 tests, except for calcium. Comparison of the total analytical error with the medically allowable error at a decision value showed that the test results were acceptable, except for calcium and phosphorus. The instrument showed good reliability and practicability.