The H-Point Standard Additions Method When the Matrix Effect is Absent. Application to the Determination of Certain Cephalosporins and their Acid-Induced Degradation Products

Abstract

This paper discusses the requirements and scope of application of the H-point Standard Additions Method (HPSAM) when the matrix effect is absent. It is demonstrated that the HPSAM calibration method works well with slopes of calibration graphs as standards. It is applied to the resolution of binary mixtures of intact and acid degraded cephalosporins. The results obtained are better than those obtained by second derivative spectrophotometry.

Key Words:

• H-point standard additions method
• bias error
• spectrophotometry
• intact and acid-degraded cephalosporins