24小时热门版块排行榜    

查看: 1840  |  回复: 3

yzhlasiI

铁虫 (正式写手)

[求助] 气相色谱检测方法问题,请教大家!!

这个方法是做顶空的吗?
各位老师,帮帮忙,小弟是新手。

这是整个气相方法:
TESTS
pH (2.2.3): 6.5 to 7.5.
Dissolve 0.20 g in carbon dioxide-free water R and dilute to
10 mL with the same solvent.
Impurity C. Gas chromatography (2.2.28).
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.
Reference solution (a).Dissolve5.0mgof sodium
phenylbutyrate impurity C CRS in methylenechlorideR and
dilute to 10.0 mL with the same solvent.
Reference solution (b). Dilute 1.0 mL of reference solution (a)
to 10.0 mL with methylenechlorideR.Place1.0mLofthis
solution in a vial with a screw cap, evaporate to dryness and
add 0.5 mL of the silylation solution. Seal the vial and heat at
70±5°Cfor20min.
Reference solution (c). Dissolve 10 mg of the substance to be
examined in 25 mL of water R. To 3 mL of this solution add
0.1 mL of hydrochloric acid R. Extract with 2 quantities, each
of 5 mL, of methylene chloride R. Combine the methylene
chloride extracts in a vial with a screw cap and add 2 mL of
reference solution (a). Evaporate to dryness and add 0.5 mL of
the silylation solution. Seal the vial and heat at 70 ± 5 °C for
20 min.
Column:
— material :fusedsilica;
— size: l =25m,?=0.25mm;
— stationary phase: poly(dimethyl)(diphenyl)siloxane R (film
thickness 1.0 μm).
Carrier gas : helium for chromatography R.
Flow rate:0.9mL/min.
Split ratio: 1:100.
Temperature:
                        Time(min)        Temperature(°C)
Column               0-5                 50
                           5 - 27               50 → 270
                         27 – 32            270
Injection port                            270
Detector                                    270
Detection:flameionisation.
Injection:1 μL.
Relative retention with reference to phenylbutyrate (retention
time = about 20 min) : impurity C = about 0.98.
System suitability: reference solution (c) :
— resolution: minimum 3.0 between the peaks due to
impurity C and phenylbutyrate.
Limit :
— impurity C:notmorethantheareaofthecorresponding
peak in the chromatogram obtained with reference
solution (b) (0.1 per cent).
Related substances. Liquid chromatography (2.2.29).  


这个方法是不是顶空方法,如果是的话,里面怎么没有顶空条件?难道是硅烷化反应的条件就包含了顶空条件(Seal the vial and heat at 70 ± 5 °C for 20 min.)还是说顶空条件要自己摸索?
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

nanjingzyf

铁虫 (初入文坛)

【答案】应助回帖


感谢参与,应助指数 +1
408851978(金币+1): 新人奖,鼓励应助 2012-02-09 10:48:23
直接进样1ul 看进样量就可以了呀
2楼2012-02-09 09:19:12
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yzhlasiI

铁虫 (正式写手)

引用回帖:
2楼: Originally posted by nanjingzyf at 2012-02-09 09:19:12:
直接进样1ul 看进样量就可以了呀

如果是直接进样,那样品处理这样合理吗?用5ml二氯甲烷萃取2次后,于10ml螺丝帽玻璃容瓶中蒸干萃取物中残留的二氯甲烷,加入0.5ml硅烷化溶液。密封玻璃瓶放置于70±5。C的烘箱中加热20min.这样处理后再转移到1.5ml小玻璃瓶中进样分析,这么小的体积好转移吗?不转移的话,能直接进样吗,10ml的瓶子0.5ml左右的体积?
3楼2012-02-09 13:27:31
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

apm19861204

金虫 (小有名气)

【答案】应助回帖


感谢参与,应助指数 +1
西湖醉鱼(金币+1): 欢迎来分析版指导 2012-02-09 17:33:01
你这个不是顶空  是硅烷化的预处理哎  你是不是还发了一个帖子问单糖的GC分析  这个就是单糖的预处理方法之一   我以前做的用的是甲酰化  那个问道比较重  你这个方法我没有用过  但是很类似  也需要密封后在烘箱中加热反应后  进样的
4楼2012-02-09 17:01:38
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 yzhlasiI 的主题更新
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 328求调剂,英语六级551,有科研经历 +6 生物工程调剂 2026-03-17 10/500 2026-03-22 20:22 by edmund7
[考研] 311求调剂 +6 冬十三 2026-03-18 6/300 2026-03-22 20:18 by edmund7
[考研] 324求调剂 +6 lucky呀呀呀鸭 2026-03-20 6/300 2026-03-22 16:01 by ColorlessPI
[考研] 能源材料化学课题组招收硕士研究生8-10名 +5 脱颖而出 2026-03-16 17/850 2026-03-22 15:18 by 脱颖而出
[考研] 297求调剂 +3 喜欢还是不甘心 2026-03-20 3/150 2026-03-21 18:33 by 学员8dgXkO
[考研] 311求调剂 +3 勇敢的小吴 2026-03-20 3/150 2026-03-21 17:40 by ColorlessPI
[考研] 265求调剂 +12 梁梁校校 2026-03-19 14/700 2026-03-21 13:38 by lature00
[考研] 一志愿华南师大 070300(化学)304分求调剂 +3 0703武芊慧雪304 2026-03-18 3/150 2026-03-21 00:48 by JourneyLucky
[考研] 288求调剂 +16 于海海海海 2026-03-19 16/800 2026-03-20 22:28 by JourneyLucky
[考研] 317求调剂 +5 申子申申 2026-03-19 9/450 2026-03-20 22:26 by JourneyLucky
[考研] 085600材料与化工 +8 安全上岸! 2026-03-16 8/400 2026-03-20 22:13 by luoyongfeng
[考研] 求调剂一志愿南京航空航天大学289分 +3 @taotao 2026-03-19 3/150 2026-03-20 21:34 by JourneyLucky
[考研] 材料学硕297已过四六级求调剂推荐 +11 adaie 2026-03-19 11/550 2026-03-20 21:30 by laoshidan
[考研] 材料学求调剂 +4 Stella_Yao 2026-03-20 4/200 2026-03-20 20:28 by ms629
[考研] 一志愿西安交通大学 学硕 354求调剂211或者双一流 +3 我想要读研究生 2026-03-20 3/150 2026-03-20 20:13 by JourneyLucky
[考研] 广西大学家禽遗传育种课题组2026年硕士招生(接收计算机专业调剂) +3 123阿标 2026-03-17 3/150 2026-03-20 15:58 by 飞行琦
[考研] 085410人工智能专硕317求调剂(0854都可以) +4 xbxudjdn 2026-03-18 4/200 2026-03-20 09:07 by 不168
[考研] 312求调剂 +8 陌宸希 2026-03-16 9/450 2026-03-18 12:39 by Linda Hu
[考博] 26博士申请 +3 1042136743 2026-03-17 3/150 2026-03-17 23:30 by 轻松不少随
[考研] 有没有道铁/土木的想调剂南林,给自己招师弟中~ +3 TqlXswl 2026-03-16 7/350 2026-03-17 15:23 by TqlXswl
信息提示
请填处理意见