Question for NH2P-50 4E Column

Record: 914

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Category: Column Problem
Product: NH2P-50
Sample:

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Question
Question for NH2P-50 4E Column

 
 

Answer
Our tech support in Japan seems to think the matrices in the unknown sample may affect the reproducibility of the elution of mannitol. We would like to know if the standard solution is reproducible after five injections. Do you see the same results?

It is true that the NH2P-50 column takes a little longer to equilibrate than other columns. If the peak area is changed by the injections of the standard solutions and you need to save time for the analysis, our tech support recommends to store the column with the eluent you are using for the analysis.

Please let me know about the reproducibility of your standard solution.

Best Regards,
Melissa

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Melissa Turcotte, Ph.D.
Sales & Technical Support
Shodex HPLC column
Showa Denko America, Inc.
420 Lexington Ave Ste 2335A
New York, NY 10170
mturcotte@shodex.net
212-370-0033×109
www.shodex.net
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From: Zhang, Lifeng [mailto:lifeng_zhang@baxter.com]
Sent: Friday, March 07, 2014 10:01 AM
To: Melissa Turcotte
Subject: RE: Question for NH2P-50 4E Column

Hi, Melissa,

I don’t understand well the first question.

The first peak area could be 165000 all others injections peak area are around 175000. I tried difference standard preparation in different days sometimes got similar results.

Lifeng

From: Melissa Turcotte [mailto:mturcotte@shodex.net]
Sent: Thursday, March 06, 2014 8:36 AM
To: Zhang, Lifeng
Subject: Re: Question for NH2P-50 4E Column

Dear Lifeng,

My tech support in Japan would like to know if each injection I waged with ACN. I do no think so, but I have I check.

Also, how much smaller peak area is the first injection? Have you tried making two consecutive standard mannitol injections for comparison?
Thanks
Melissa
Sent from my iPhone

On Mar 5, 2014, at 9:34 AM, “Zhang, Lifeng” wrote:
Melissa,

Thank you for your reply.

The first peak are is smaller than other five following peaks. Other five peak showed same peak area. There was no down trend there.

Lifeng

From: Melissa Turcotte [mailto:mturcotte@shodex.net]
Sent: Wednesday, March 05, 2014 7:12 AM
To: Zhang, Lifeng
Subject: Re: Question for NH2P-50 4E Column

Hi Lifeng,
I have forwarded your inquiry to our tech support in Japan. Thank you for your patience.

When you say the first injection is lower, do you mean the peak area is lower? Are the other four injection of the same peak area? Or do thy show done trend?

Thank you,
Melissa

Sent from my iPhone

On Mar 4, 2014, at 4:22 PM, “Zhang, Lifeng” wrote:
Hi, Melissa,

I am now using NH2P-50 4E Column for Mannitol with 65% ACN as mobile phase. I found my first injection of system suitability is always lower than other 5 following injections. I purge my waters alliance system for 5ml/ml for 8 minutes and condition the column with 3 injection of water and my Mannitol control.

We used 100% ACN wash this column after last run. My question is why it takes so long to condition this column.

 
 
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