For derivatization, the eluted sterols and stanols were dried completely under a gentle flow of nitrogen before adding 100 [micro]L 99:1 BSTFA+TMCS (N,O-Bis(trimethylsilyl) trifluoroacetamide and Trimethylchlorosilane
), then heated at 60[degrees]C for two hours.
The sample was subjected to derivatization with N,O-bistrimethylsilyl trifluroacetamide and trimethylchlorosilane
. Derivatized samples were injected into a Shimadzu QP-2010 Plus GC-MS operating in split mode.
Unsaponifiables were mixed with 0.5 mL of BSTFA (N, O-bis(trimethylsilyl)trifluoroacetamide + trimethylchlorosilane
) that contained 1% trimethylsilyl chloride and 1 mL pyridine, and dissolved again, followed by induction of reaction at 80[degrees]C for 1 h.
The organic extracts were evaporated to 1.0 mL, and then an aliquot of 50.0 [micro]L was derivatized using bis(trimethylsilyl) trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane
(TMCS) for 120 min at 70[degrees]C.
 obtained a value of 135[degrees] for pine needle nanofiber aerogels obtained by the treatment of trimethylchlorosilane
through vapor phase deposition.
Internal standard (5[beta]-cholestane, Sigma-Aldrich) was added to the samples and then the sample was derivatized with N,O-Bis(trimethylsilyl) trifluoroacetamide with trimethylchlorosilane
(Sigma-Aldrich, 99% BSTFA + 1% TMCS).
N,O-Bis(trimethylsilyl) trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane
(TMCS) of analytical grade was from Regis (Morton Grove, IL, USA).
Hexamethyldisilazane, pyridine, trimethylchlorosilane
, and standards of [alpha]-, [gamma]-, [beta], and ([delta]-tocopherol were from Merck (Merck Group, Darmstadt, Germany).
The top hexane layer was transferred into borosilicate tubes and evaporated under a stream of argon gas, followed by the addition of N,0-bis(trimethylsilyl)trifluoroacetamide in 1% trimethylchlorosilane
. A 1 [micro]L aliquot was injected onto the column.
N,O-bis(trimethylsilyl) trifluoroacetamide containing 1% trimethylchlorosilane
, used for preparation of trimethylsilyl (TMS) ether derivatives of sterols, was obtained from Supelco (Bellefonte, PA).
The dried sample was then mixed with 200 [micro]L of pyridine and 100 [micro]L of Sylon bis (trimethylsilyl) trifluoroacetamide (99% bistrifluoroacetamide+1% trimethylchlorosilane
and derivatized at 50[degrees]C for 1 h.
HCl, used or formed as a by-product when trimethylchlorosilane