Stored  Standard
        Standard Peaks Contaminant Peaks

Derivatized

Underivatized

Underivatized

Unknown

7-ketoa

7-keto tms ether

7-keto

7-keto
3,5-7-oneb

 

 

19-OHc

19-OH tms ether

 

 

19-OH Related

Triold

Triol tms ether

 

 

Triol Related

a7-ketocholesterol, b7-keto cholesta-3,5-dien-7-one, c19-hydroxycholesterol and dcholestane-3β-5α,6β-triol
Table 1: Peaks observed from the original standards after storage and derivatization.