Page 456 - Handbook of Materials Failure Analysis

454 CHAPTER 17 Application of pyrolysis

Table 17.2 Identification and Content of the Investigated Motor Vehicle
Brake Fluids
Content, % (w/w)
Retention Time Identified Compound Good Claimed
(RT) (min) (Trimethylsilyl Derivate) Functioning Brake
Brake Fluid Fluid

10.43 Boric acid 17.41 9.87
14.96 Diethylene glycol 10.64 11.26
16.36-16.37 Bis(2-hydroxyethyl)methylamine 0.40 1.21
17.18-17.20 Triethylene glycol monomethyl ether 46.37 46.58
19.23-19.24 Triethylene glycol 0.61 1.81
20.77 Triethylene glycol monobutyl ether - 3.55
21.28-21.30 Tetraethylene glycol monomethyl ether 15.90 14.09
23.07 Tetraethylene glycol 0.28 2.45
24.50 Tetraethylene glycol monobutyl ether - 1.62
24.93-24.94 Pentaethylene glycol monomethyl ether 3.78 2.94
26.49 Pentaethylene glycol - 0.21
27.83 Pentaethylene glycol monobutyl ether - 0.47
Others 4.61 3.94

FIGURE 17.7
Chemical structure and mass spectrum of trimethylsilyl derivate of triethylene glycol
monomethyl ether (main ingredient) identified in the examined motor vehicle brake fluids.
GC/MS apparatus 2 and analytical conditions as in p. 2.3.