Analysis of the Ortho-Isomer of Tri-Cresyl Phosphate in Commercial Tri-Cresyl Phosphate Additives

摘要

Hydraulic fluid qualified under Mil Specs MIL-H-46170B and MIL-H-6083E may contain antiwear agents, such as tri-cresyl phosphate (TCP). When TCP is used, it should contain not more than 1% of the ortho-isomer to comply with OSHA guidelines for handling. This report covers methods of monitoring the percentage of the ortho-isomer in commercial TCP products. A high performance liquid chromatograph (HPLC) method was developed using a normal phase column. The analysis results of six commercial TCP products found that the products contained only trace amounts or less than 1% of ortho-isomer, and this fully meets OSHA guidelines. The results of infrared (IR) and carbon-13 nuclear magnetic resonance (NMR) analysis are also shown. Both spectroscopic methods can be used to determine the p resence of ortho-TCP in commercial TCP products. Keywords: Hydraulic fluids, Tri-Cresyl Phosphate (TCP), High performance liquid chromatograph, Infrared, Nuclear magnetic resonance.