Silanol, trimethyl-, formation

Silanediol, diphenyl-, 3 62 Silanol, trimethyl-, formation of, by hydrolysis of hexamethyl-disilazane, 5 58... 

In addition to the solvent, additives are often used in HPLC in low amounts (0.01-1%) to optimize performance and minimize undesired side effects, such as peak broadening. One of the prime factors determining retention is the charge state of the analyte that strongly depends on the pH. For this reason buffers (traditionally potassium phosphate buffers) are typically used to adjust the pH accurately. Note that in the case of HPLC-MS, nonvolatiles cannot be used, so typically ammonium acetate or formate buffer is preferred. Various other additives may also be used, such as trimethyl amine or trifluoroacetic acid, to suppress the interaction of analytes with the residual silanol groups of the stationary phase, thereby improving the resolution. 

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