Method for Determining Glucose in Plasma, Cerebrospinal Fluid, and Urine by Means of P-Bromaniline

Abstract

This paper describes a rapid, accurate, and cheap micro-method for determining glucose in plasma, cerebrospinal fluid, and urine—well-suited for automation. Its principle is that during heating with acetic acid the glucose is converted to a furfurol forming with p-bromaniline a yellowish colour which at 380 nm has a well-defined absorption maximum. A precision study shows a coefficient of variation of 1.6 on blood levels of glucose around 100 mg/100 ml. The day-to-day reproducibility for a serum sample with a glucose content of 178 mg/100 ml is ±4.5%. The specificity is elucidated 1) by experiments using addition of glucose to whole blood and urine. (The correlation coefficients between the measured amount of glucose and the expected amount are 0.98 and 0.99 respectively.) 2) By comparison of glucose levels in plasma and blood determined by the new method and by the glucose oxidase method. The glucose concentration measured in deproteinized plasma was identical with the plasma glucose concentration measured by the glucose oxidase method.

Key Words:

• Blood sugar
• glucose
• spectrophotometry