Hi, In theory when an HPLC mobile phase is flowing there is an uninterupted flow of mobile phase which produces a constant stream of mobile phase. With ...
shiffty@...
Jun 2, 2003 12:41 am
1596
Hi, If you have an equilibrated HPLC system with relatively Gaussian peaks and you increase the flow rate the area should not change. The peak height will ...
shiffty@...
Jun 2, 2003 12:52 am
1597
Dear shiffty, I do not agree with your statement. The same discussion has taken place in the same forum long back. By increasing the flow rate relatively the...
M SRINIVAS REDDY
srinureddi@...
Jun 2, 2003 4:36 am
1598
I am sorry, your interpretation is wrong. First, for a years the injection valves do not cause any flow interruption during switching because of so called MBB...
Milan Minárik
m_minarik@...
Jun 2, 2003 8:54 am
1599
... From: Hans W. Mueller <Hans.W.Mueller@...> To: <shiffty@...> Sent: Monday, June 02, 2003 3:32 PM Subject: Re: [chrom-L] (unknown)...
Hans W. Mueller
Hans.W.Mueller@...
Jun 2, 2003 1:47 pm
1600
Both of you are right. The double the flowrate and the area (counts*time) halves. But if one calculates area in counts*mL, then the area is constant. Time *...
Robert.M.Hofeldt@...
Jun 2, 2003 4:02 pm
1601
Dear All, we have recently encountered problems when performing the European Pharmacopoeial Insulin assay and test for related proteins. The later employs a ...
john.kennedy@...
Jun 3, 2003 6:05 am
1602
I think we need to go back to the way a detector/integrator system works. First the analogue signal from the detector is digitised. The rate of digitisation...
I did now, Peter. Thanks. I had clicked on reply before but I guess it just went to you. So here is to all to view. Please read down below. Al ... From: Peter...
Al Welch
alwelch@...
Jun 3, 2003 10:56 pm
1604
There is a good review of this subject in Journal of Chrom. A, (2002) 219-232. Well worth a read as it's easy to take this stuff for granted. Patrick Boyce ...
Dear Quaxtar It is true that on a concentration dependant detector, such as most HPLC detectors, doubling the flow will not help your peak area as it might on...
Dirk Holstege
dmholstege@...
Jun 6, 2003 12:32 pm
1606
Dear Milan, This question has come up to me before. Could you please explain why a peak appears when just turning the injection valve to inject from run, when...
Dirk Holstege
dmholstege@...
Jun 6, 2003 12:32 pm
1607
Dear all, I am trying to isolate some phenolic compounds from my organic solvent soluble fraction using reversed phase silica gel CC. Can anybody suggest me...
vijay punjabi
hero_032002@...
Jun 6, 2003 12:48 pm
1608
Researchers, I am interested in connecting my HPLC system with computer. Please suggest some good quality chromatography package which can handle data from UV...
QC Analytical Chemist in the Greater Boston Area. The QC analyst will perform analytical testing on raw materials, product in process and finished goods in...
John Rynak
jtrynak@...
Jun 6, 2003 12:49 pm
1610
Dear all member Chrom-L, I would like to ask about system peaks in chromatogram. does it can caused of eluent composition? Thanks...
I would like to know if someone has information about Lectins methods resistain to pH and temperture degradation or Proteolitic degradation. I 'll be very...
First, a brief introduction since I'm new here: I'm the new, lone system administrator for all of the lab systems (LIMS, chromatography system, etc.) in a...
Chris Labelle
CLabelle@...
Jun 18, 2003 3:05 pm
1614
Hello, I am developing a method for the sunscreen active octinoxate. Everything looks good in my chromatograms except for the most important part: my assay...
Dear Friends I´m needing spectral and chromatographic data about the evaluation of atovaquone. The medicne is best known as MALARONE and is an association...
Hi Chris, The usual technique to avoid this problem is to use a remote start cable: Connect the "Inject Start" output of the Alliance with the appropriate...
Martina.Oefelein@...
Jun 18, 2003 4:38 pm
1617
Hello, Wouldn't the sunscreen active octinoxate be degraded by light, and hence result in poor recovery? Are you using amber colored vials? How about wrapping...
Dear All We are wanting to measure the degradation of the above polymer via HPLC. However to create standards we are getting conflicting information about the ...
Hello,everyone,who ever detect monoamine (eg:serotonin,dopamine,NE et al).If you ever did,please tell me the mobile you used . Thanks,in advance. ... Do You...
Dear all, I am using a GPC as a clean-up step in some of my sample preparation procedures. From time to time I have to check the performance of the GPC with a...
Thanner Gerhard
thanner@...
Jun 20, 2003 7:39 am
1621
Hi, How are you preparing your sample? At our facility we have a lot of practice with creams and ointment sample preparations and the one thing that I have...
The Shifflet's
shiffty@...
Jun 21, 2003 11:41 am
1622
I've found that the most frequent source of lousy recovery on sunscreens may usually be found in the sample prep. You don't mention your sample matrix, but...
I am happy with WinDaq from Dataq instruments: www.dataq.com 50$ (US) and its pretty sophisticated I do not work for DATAQ, I only bought their AD connector...
I have developed an ActiveX library that allows the loading and utilization of AIA (netCDF) formatted files natively in Visual Basic or any other environment...
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