Dear Analysts, I am trying to determinate n-alkanes, from C10 up to C34 (mainly C20-C32) in particulate matter of tobacco smoke, using HP 5890(II)GC attached...
Maybe these guys: http://www.accustandard.com/ MARIA K <kalaitzoglou@...> wrote: Dear Analysts, I am trying to determinate n-alkanes, from C10 up to C34...
Hi,
We use pure water for our mobile phase, and we routinely have negative peaks. We are using an Agilent HP-1100 system, what type of system are you...
The Shifflet's
shiffty@...
May 1, 2002 8:19 pm
1210
Hi, there! I use HPLC 1090L to analyze a drug. In the first 4 months it worked fine then it stopped giving me any decent peaks even with standard samples. The...
Good morning, Without more specific information it's hard to make a recommendation. Generically your problem is know as "Poor Sample Recovery." Possible...
To whom responses should be sent : DZurbriggen@... ___________________________________________________________ Dear colleagues, I am in the process of...
Good afternoon, A guard column is a short (about 5 cm) column, packed with a stationary phase identical or similar to that of the analytical column. Installed...
Dear All, I have been using L19 equivalent column for Mannitol Assay by following USP method. But I always get the problem of poor peak shape of Mannitol ,...
krishnamohanchvs@...
May 4, 2002 8:28 am
1215
Hi, Do you use the LC system that you are using for USP manitol / sorbitol method for other types of assays? If so you may want to try washing your system...
The Shifflet's
shiffty@...
May 6, 2002 8:21 am
1216
Diego, my preffered approach will be: UV detection at low wavelenghts - 205-215 nm (chloride absorbs at 190-200 nm, bromide up to cca 220 nm) high capacity...
Ivan Vins
i_vins@...
May 6, 2002 8:22 am
1217
Dear Krishna, this application should work (its USP method) on any Ca form sulfonated 8% styrenedivinilbenzene column. Some posible reasons for your problem:...
Ivan Vins
i_vins@...
May 6, 2002 8:22 am
1218
Hello. I'm looking for a supplier of Troxerutin HPLC reference standard. Does anyone knows a supplier of it ? Thank you. Rodrigo Dias Martins - Brazil. ... Use...
Hi. I'm looking for Coumarin HPLC reference standard to buy. Does anyone knows a supplier of it ? Thank you in advance. Rodrigo Dias Martins - Brazil ... Use o...
Rodrigo, We try the following source first: INDOFINE Chemical Company P.O. Box 473 Somerville, NJ 08876 USA 888-463-6346 908-359-1179 FAX ...
David Bligh
dbligh@...
May 6, 2002 2:58 pm
1222
Hi, I was hoping someone could help me understand an SOP I came across. Ufortunatly the originator is not available. Basically a standard is made by diluting...
Good morning, If I came across a procedure that listed a linear range I would believe it to be a statement of the range of concentration to which the detector...
Hello. I'm trying to quantify the coumarin (Raw-material) by the DAB 10 titrimetric method, but I'm not having good results. I tried with the indicator...
There may be confusion here between target range and linear range. As already mentioned by others, the linear range is the whole range over which one should...
I am using Rhodamine to label a peptide and get lots of fluorescence-peaks at RPHPLC. Now the question: Has anyone worked with this so far, that he could give...
Hi Chromatographers Could somebody help me with parameters for liquid or TLC separation of tertiary amines - alquil dimetil amines, where the alquil groups...
I just ran a drug standard on an Agilent GC/MS and went to the mass spectrum screen for the peak and at the top of the screen there is the word "Corrupt"....
Dear members of this forum, I know the anaylisis of selenium in water has some dificulties using graphite furnace atomic absorption. I have to read some...
DRDN
tequila2@...
May 19, 2002 9:57 am
1230
That just means that the MSD was overloaded and that the spectrum acquired is not going to be very accurate. By overloaded I am referring to introducing too...
jason_ellis@...
May 19, 2002 10:02 am
1231
Dear colleagues, I am looking for a method to analyze dichlorodimethylhydantoin (DCDMH) for the bromo-chloro-dimethylhydantoin and dibromo-dimethylhydantoin...
DZurbriggen@...
May 19, 2002 9:33 pm
1232
Hi I want to know which is the best diluting solvent for a HPLC assay preparation for water soluble vitamins? I found a column that allow me to have a good...
Hi Diego Have just had a quick look at the structures. 1. HPLC on a reverse phase system with UV or photodiode array detection should work, and would be the...
Does anyone know where or when "Chiral HPLC Traning", "short course", or "Symposium" is held?...
kyoungq
kyoungq@...
May 23, 2002 9:02 am
1235
I have been trying to resolve alpha lactams on Phenomenex Pirkle column using normal phase HPLC. Mobile phase is n-hexane and IPA. does anyone have an idea...
Dear colleagues, We are experiencing problems reproducing a chiral separation that was run successfully on our Chromtech chiral AGP column a few years ago....
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