24小时热门版块排行榜    

查看: 5125  |  回复: 9

yxh-5566

铜虫 (初入文坛)

[求助] 液质正模式分析一个化合物,分子量增加46 会是加了2个钠吗

如题,一个分子上能加两个钠吗
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

organicsuper

木虫 (正式写手)

【答案】应助回帖

★ ★
感谢参与,应助指数 +1
crity328: 金币+1, 感谢交流,欢迎常来~ 2012-12-21 21:21:01
yxh-5566: 金币+1, ★★★很有帮助 2012-12-24 12:39:39
加2个Na也可以,但是就要出双电荷峰,即主峰跟同位素峰(也就是M+1)峰之间的间距是0.5m/z.其它的貌似没有46的分子加上去.如果可是溶剂分子,那么去问问做质谱的老师用的是啥溶剂.
2楼2012-12-21 19:06:35
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

lzjessie_wlf

金虫 (小有名气)

【答案】应助回帖


感谢参与,应助指数 +1
yxh-5566: 金币+1, ★★★很有帮助 2012-12-24 12:39:57
The 46 difference from your single-charged compound [M+H] normally should come from the formic acid adduct [M+H+HCOOH] since formic acid (or TFA) is added for positive mode in ESI.

Only 22 differentiated from the [M+H] peak if a sodium was added, and 44 differentiated from the [M+H] peak if two sodium were added for single charged peak.
  For double charged peak, the m/z for it should be [M+Na+Na]/2 since two positive charge have been attached.
the difference between isotope pattern should be 0.5 instead of 1 for single charged peak.
3楼2012-12-21 23:56:09
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

zzjcust

铁杆木虫 (正式写手)

【答案】应助回帖


感谢参与,应助指数 +1
yxh-5566: 金币+1, ★★★很有帮助 2012-12-24 12:40:14
要是加钠是不是带两个电荷了,质荷比就不对了,加甲酸的可能性大一些,
4楼2012-12-22 07:17:16
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yxh-5566

铜虫 (初入文坛)

引用回帖:
2楼: Originally posted by organicsuper at 2012-12-21 19:06:35
加2个Na也可以,但是就要出双电荷峰,即主峰跟同位素峰(也就是M+1)峰之间的间距是0.5m/z.其它的貌似没有46的分子加上去.如果可是溶剂分子,那么去问问做质谱的老师用的是啥溶剂.

谢谢回复
5楼2012-12-24 12:26:55
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yxh-5566

铜虫 (初入文坛)

引用回帖:
3楼: Originally posted by lzjessie_wlf at 2012-12-21 23:56:09
The 46 difference from your single-charged compound  normally should come from the formic acid adduct  since formic acid (or TFA) is added for positive mode in ESI.

Only 22 differentiated from the ...

谢谢
6楼2012-12-24 12:27:21
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

yxh-5566

铜虫 (初入文坛)

引用回帖:
4楼: Originally posted by zzjcust at 2012-12-22 07:17:16
要是加钠是不是带两个电荷了,质荷比就不对了,加甲酸的可能性大一些,

哦,多谢
7楼2012-12-24 12:28:15
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

valley_chow

金虫 (正式写手)

【答案】应助回帖


感谢参与,应助指数 +1
yxh-5566: 金币+1, ★★★很有帮助 2012-12-26 16:46:10
引用回帖:
3楼: Originally posted by lzjessie_wlf at 2012-12-21 23:56:09
The 46 difference from your single-charged compound  normally should come from the formic acid adduct  since formic acid (or TFA) is added for positive mode in ESI.

Only 22 differentiated from the ...

M+Na就直接是带电荷的离子了,没有多加一个氢了,你用22和44来打比方都是不对的,只有聚乙二醇化合物才会有+22和+44的。
8楼2012-12-24 12:33:31
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

ouyanggan

新虫 (小有名气)

引用回帖:
3楼: Originally posted by lzjessie_wlf at 2012-12-21 23:56:09
The 46 difference from your single-charged compound  normally should come from the formic acid adduct  since formic acid (or TFA) is added for positive mode in ESI.

Only 22 differentiated from the ...

I also have some problem ,product exact mass is 258,but get ESI(+) result is 304, M+46;if as you said : [M+H+HCOOH] =M+47,can you explain this?
9楼2022-08-08 11:32:23
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

ouyanggan

新虫 (小有名气)

引用回帖:
3楼: Originally posted by lzjessie_wlf at 2012-12-21 23:56:09
The 46 difference from your single-charged compound  normally should come from the formic acid adduct  since formic acid (or TFA) is added for positive mode in ESI.

Only 22 differentiated from the ...

I also have some problem ,product exact mass is 258,but get ESI(+) result is 304, M+46;if as you said : [M+H+HCOOH] =M+47,can you explain this?
10楼2022-08-08 11:35:08
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 yxh-5566 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] 341求调剂(一志愿湖南大学070300) +5 番茄头--- 2026-03-22 6/300 2026-03-23 23:45 by Txy@872106
[考研] 材料调剂 +3 匹克i 2026-03-23 3/150 2026-03-23 23:18 by peike
[考研] 一志愿国科过程所081700,274求调剂 +3 三水研0水立方 2026-03-23 3/150 2026-03-23 23:11 by MajorWen
[考研] 328求调剂,英语六级551,有科研经历 +7 生物工程调剂 2026-03-17 12/600 2026-03-23 18:18 by YMU施老师
[考研] 328求调剂 +4 LHHL66 2026-03-23 4/200 2026-03-23 14:55 by lbsjt
[考研] 306求调剂 +5 来好运来来来 2026-03-22 5/250 2026-03-22 16:17 by BruceLiu320
[考研] 求调剂 +5 Zhangbod 2026-03-21 7/350 2026-03-22 13:13 by Zhangbod
[考研] 303求调剂 +5 安忆灵 2026-03-22 6/300 2026-03-22 12:46 by 素颜倾城1988
[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] 313求调剂 +4 肆叁贰壹22 2026-03-19 4/200 2026-03-21 17:33 by ColorlessPI
[考研] 求调剂 +6 Mqqqqqq 2026-03-19 6/300 2026-03-21 08:04 by JourneyLucky
[考研] 083200学硕321分一志愿暨南大学求调剂 +3 innocenceF 2026-03-17 3/150 2026-03-21 02:35 by JourneyLucky
[考研] 一志愿华中科技大学,080502,354分求调剂 +5 守候夕阳CF 2026-03-18 5/250 2026-03-21 01:06 by JourneyLucky
[考研] 294求调剂材料与化工专硕 +15 陌の森林 2026-03-18 15/750 2026-03-20 23:28 by JourneyLucky
[考研] 考研调剂求学校推荐 +3 伯乐29 2026-03-18 5/250 2026-03-20 22:59 by JourneyLucky
[考研] 295复试调剂 +8 简木ChuFront 2026-03-19 8/400 2026-03-20 20:44 by zhukairuo
[考研] 求调剂 +3 @taotao 2026-03-20 3/150 2026-03-20 19:35 by JourneyLucky
[考研] 0703化学调剂 +4 18889395102 2026-03-18 4/200 2026-03-19 16:13 by 30660438
[考研] 材料考研调剂 +3 xwt。 2026-03-19 3/150 2026-03-19 11:22 by w沐阳w
信息提示
请填处理意见