Dear Alvicler
Thank you very much for your comments. I have attached the related one dimensional NOE spectra. I hope somebody could help me out.
Considered the questions, I would like to describe them one by one
(1) How about the selectivity of the pulse? For this question, I simply follow Bruker's manu. First calculate the 90 degree hard pulse of proton, then fill this value in the prosol table. I have choosen the 180 degree selective pulse with Gaussion1.180r.1000. I have teset several values of pulse, for example, 5, 10, 15, 20, 25 and 30 Hz. However, none of them give me a reasonable results.
(2) I have attached the proton spectrum, the position irradiated is located at position 1. This proton is coupled with another proton at position 2. I tried to evaluate the NOE enhancement of proton at position 2.
(3) I am a little innocent about the shaped pulses. I am also tried other selective pulse instead gauss1.180r.1000, for example, Q3.1000, Rsnob.1000, Reburp.1000 and bip720,50,20.1. They also offered me the same results.
I don't know if the information provided is clear enough. If there were any idea, I could attached more data next time.
Best regards
Junfeng Xiang
NMR Lab, ICCAS， China
> -----原始邮件-----
> 发件人: "Alvicler Magalhães" <alvicler_at_uol.com.br>
> 发送时间: 2015年2月5日 星期四
> 收件人: "Tatiana Agback" <tatiana.agback_at_medivir.com>, jfxiang_at_iccas.ac.cn
> 抄送:
> 主题: Re: AMMRL: about one dimension selective NOE experiment to suppress selective population transfer
>
> Dear Fellows,
> I have some questions and this could provide the final answer for the problem, but please let me know more to help on it.
> How selective the pulse needs to be? We are talking about 10Hz, 100Hz, more then it?
> How you calibrate it?
> What kind of shaped pulse are you using for it?
> Could you send me more infos like 1D spectrum and the regions to make selective pulse?
> thanks in advance
> Regards
> Alvicler
>
>
>
> > On Feb 4, 2015, at 7:09 AM, Tatiana Agback <tatiana.agback_at_medivir.com> wrote:
> >
> > Hi
> > I have observed this effect too. Can not get good bruker pulse sequence.
> > I would appreciate if those who have an answer for Junfeng Xiang put me as CC in e.mail
> >
> > Regards
> >
> > Tatiana
> >
> > Tatiana Agback, Ph.D.
> > Associate Director NMR
> > <image001.jpg>
> > Direct: +46 8 54683172
> > Mobile: +46 70 2235993
> >
> > From: jfxiang_at_iccas.ac.cn [mailto:jfxiang_at_iccas.ac.cn]
> > Sent: den 3 februari 2015 04:37
> > To: ammrl_at_ammrl.org
> > Subject: AMMRL: about one dimension selective NOE experiment to suppress selective population transfer
> >
> > Hello, everyone
> >
> > Recently, I have encountered a problem with selective NOE experiment. I want to determine the NOE enhancement of coupled protons by irradiating its coupled partners. However, the NOE spectrum has shown large anti-phase contribution from selective population transfer (SPT effect). Therefore, I couldn't obtain a reliable data about NOE enhancement. I have tried several methods in the Bruker pulse library, for example, selnogp, selnogpzs, selcssfnozs.2. All of them gave me the identical results. I have consulted with the literature, and found there were some possible methods in eliminating this unwanted antiphase cntribution (Fig 8 in J Magn Reson 125, 302-324, 1997). However, this pulse program is not available in Bruker or Joel pulse library. I wonder if anyone have met such problem before and could offer me some hints or solution? My NMR data is processed with TopSpin 3.2pl6.
> >
> > Thank you very much!
> >
> > Junfeng Xiang
> > NMR Lab, ICCAS, Beijing China
>
Received on Wed Feb 04 2015 - 20:09:35 MST