triethylamine peak not eluted

[iHP2191]

kindly give suggestion to resolve issue regarding trimethylamine peak not eluted in sensitivity solution using DMSO as diluent and added 0.8gm of Potassium hydrogen phosphate other solvents are MDC, Toluene and benzene
column :Rtx-5 Amine (Crossbond® 5% diphenyl-95% dimethyl polysiloxane) (Make: Restek) 30m x 0.53mmx3.0μm using
Headspace methodology,the conc. of TEA was 0.3 ppm w.r.t. test solution

[Consumer Products Guy]

What's the potassium hydrogen phosphate for? Wouldn't you want to keep the triethylamine in the basic form?