24小时热门版块排行榜    

查看: 5091  |  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] 0856材料与化工,270求调剂 +7 YXCT 2026-03-01 7/350 2026-03-02 08:29 by houyaoxu
[考研] 哈工大计算机刘劼团队招生 +3 hit_aiot 2026-03-01 5/250 2026-03-02 07:48 by 得鹿梦鱼111
[考研] 高分子化学与物理调剂 +6 好好好1233 2026-02-28 13/650 2026-03-02 07:27 by 好好好1233
[考研] 欢迎采矿、地质、岩土、计算机、人工智能等专业的同学报考 +4 pin8023 2026-02-28 6/300 2026-03-02 06:35 by 汪!?!
[考研] 一志愿郑大材料学硕298分,求调剂 +5 wsl111 2026-03-01 5/250 2026-03-01 23:45 by 暮雨星晴
[考研] 材料学硕318求调剂 +5 February_Feb 2026-03-01 5/250 2026-03-01 23:31 by L135790
[考研] 江苏省农科院招调剂1名 +3 Qwertyuop 2026-03-01 3/150 2026-03-01 23:18 by aaadim
[基金申请] 成果系统访问量大,请一小时后再尝试。---NSFC啥时候好哦,已经两天这样了 +4 NSFC2026我来了 2026-02-28 4/200 2026-03-01 22:37 by 铁门栓
[考研] 0856调剂 +5 刘梦微 2026-02-28 5/250 2026-03-01 22:30 by wang_dand
[考研] 26考研报考西工大材料308分求调剂 +3 weizhong123 2026-03-01 3/150 2026-03-01 21:42 by 公瑾逍遥
[考研] 一志愿中南大学理学化学 +4 15779376950 2026-03-01 5/250 2026-03-01 19:00 by Fff-1
[考研] 0856材料求调剂 +11 hyf hyf hyf 2026-02-28 12/600 2026-03-01 18:57 by 18137688336
[考博] 26申博 +4 想申博! 2026-02-26 6/300 2026-03-01 17:32 by 想申博!
[考研] 0856材料求调剂 +4 麻辣鱿鱼 2026-02-28 4/200 2026-03-01 16:51 by caszguilin
[考研] 求调剂 +6 repeatt?t 2026-02-28 6/300 2026-03-01 14:37 by Sakura绘
[考研] 302材料工程求调剂 +4 Doleres 2026-03-01 5/250 2026-03-01 11:52 by liqiongjy
[考研] 调剂 +3 简木ChuFront 2026-02-28 3/150 2026-03-01 11:46 by 王伟要上岸啊
[考研] 317一志愿华南理工电气工程求调剂 +6 Soliloquy_Q 2026-02-28 11/550 2026-03-01 11:14 by 歌liekkas
[考研] 寻找调剂 +4 LYidhsjabdj 2026-02-28 4/200 2026-03-01 10:56 by sunny81
[基金申请] 面上模板改不了页边距吧? +5 ieewxg 2026-02-25 6/300 2026-03-01 00:10 by addressing
信息提示
请填处理意见