回复feixig11103发表于:2020/2/3 13:45:23悬赏金额:
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衍生化试剂BSTFA+TMCS的用量和比例
各位老师帮帮忙,小弟是新手
EP药典上苯丁酸钠杂质c的检测方法是做气相顶空。先用二氯甲烷萃取,蒸干后,再加硅烷化溶液进行硅烷化,具体方法如下:
Silylation solution. To 2 mL of N,O-bis(trimethylsilyl)tri-
fluoroacetamide R add 0.04 mL of chlorotrimethylsilane R
and mix.
Test solution.Dissolve50.0mgofthesubstancetobeexamined
in 3 mL of water R and add 0.5 mL of hydrochloric acid R.
Extract with 2 quantities, each of 5 mL, of methylenechlorideR.
Evaporate the combined methylene chloride extracts to dryness
in a vial with a screw cap and add 0.5 mL of the silylation
solution.Sealthevialandheatat70±5°Cfor20min.
其中
杂质c:4-cyclohexylbutanoic acid
硅烷化溶液配制方法是:N,O-双(三甲基硅烷基)三氟乙酰胺(BSTFA,CAS: 25561-30-2)里加入0.04ml三甲基氯硅烷(TMCS, CAS: 75-77-4)后混匀。
硅烷试剂不好保存,市面上有小包装卖,但规格一般为1ml BSTFA+ TMCS 99:1 。我们问题是衍生化试剂BSTFA+TMCS的用量和比例是怎么确定的?我不按药典上的方法改用1ml BSTFA+ TMCS 99:1行不行?