Hi everyone! Can someone tell me what kind of carrier and make-up gas you would use to analyse lindane (Organochlorinated pesticide) with an EC detector on a...
Mona, I'm pretty sure it will be impossible to separate bicarboante and carboante by chromatography since they are in equilibrium with each other. However, you...
Here are the specifications of my method and I sent a chromatogram of hexane for you to look at: temp 1: 100C, hold 2 min rate 1: 15C/min to 160C hold 5 min. ...
Greetings from Michigan, I'm wondering if anyone might have some ideas regarding loss of the sensitive compounds such as 2,4-dinitrophenol. If there is a new ...
Hello Everyone Could somebody tell me a method by GC or HPLC or TLC for teriary amines - dimethyl N-akyl amines where the N-Alkyl groups are C10, C12, C14, C16...
Hi there Just want to know which ELSD in the market is the most sensitive/good overall. We are planning to buy a ELSD detector and we are not sure which one is...
We are using the Alltech ELSD and have had excellent results. The Alltech tech service people were also very helpful with the connection to our HP 1100 series...
I have some problem with this column. During a gradient analisys I saw that when I increase the organic concentration in the mobile phase the baseline became...
Hi Elango, We've been looking at ELSDs for a few months, now. In addition to Alltech and Sedex, we were considering Polymer Labs and ESA. By design, Sedex is...
David Bligh
dbligh@...
Aug 7, 2002 12:13 pm
1347
Can someone help me? I'm looking for a method to analyze chlorophyll with HPLC. I have a C18 250x4.6 column and a Uv-VIs detector. I have a fluorescience ...
A classic method of analysing chlrorophyll is from Wright, Jeffrey, Mantoura, et al (1991) Improved HPLC method for the analysis of chlorophylls and...
What wavelength is your UV-Vis detector set at? It is normal for the baseline to rise as the concentration of organic modifier is increased during a gradient...
Tony Herlt
herlt@...
Aug 7, 2002 11:20 pm
1350
Hi! I've a problem with the ODS-2 column (250 x 3.00 mm, 5 micron) that I use for the detection of aflatoxins. I used to use ODS column (250 x 4.6 i.d) and...
Hi everyone, I am analysing lindane with GC-ECD and I am getting a huge solvent peak and lindane is coming out about 20 minutes later then it should be with...
the carrier gas flow may be the problem. -- On Thu, 8 Aug 2002 16:26:56 ... Is your boss reading your email? ....Probably Keep your messages private by using...
Ziqiang Wang
ziqiang@...
Aug 8, 2002 2:40 pm
1353
Hi, I'm searching for informations and internet links about fluorescience detector for HPLC. In particular I have a Milton Roy fluoromonitor III and a C18 ...
Hi! I've a problem with the ODS-2 column (250 x 3.00 mm, 5 micron) that I use for the detection of aflatoxins. I used to use ODS column (250 x 4.6 i.d) and...
I have a C18 250*4.5 and I found in internet this way to regenenerate the column: 1- reverse the column 2- flush out any salts/buffers with 25cc of pure water ...
Hello: Approximately how much do people charge for regular IC analyses - for instance inorganic anions and inorganic cations. Thank you in advance, Mona ...
This is a flash chromatography question. Does anyone on this thread have experience with, or know of journal articles related to, the formation of acetic acid...
16th August 2002 Dear colleagues, Has anyone had experience with comparing the bleed properties of the 2 GC stationary phases, OV-101 (100 % dimethylsilicone...
Tony Herlt
herlt@...
Aug 16, 2002 5:38 am
1359
10% is very high, and may be overloading the surface area of the support. Maybe try 100-120 mesh support to increase surface area. I'm guessing you have gone...
How many sample injections do people usually run between duplicate standard injections for a HPLC method used for the analysis of pharmaceuticals? I thought it...
For regular assays our company (pharmaceutical) uses an "elapsed time" approach instead. After two hours or ten sample injections, whichever comes first, ...
Rob M
drmeale@...
Aug 16, 2002 11:12 pm
1362
Conditioning at 300 C might be too high. Try 280 C. ... From: Peter Robinson [mailto:peter.robinson@...] Sent: Friday, August 16, 2002 8:24 AM To:...
Hi, We will inject 5 or 6 standards to check system precision priort to running any samples. There may be a reolution solution depending on the assay. Once...
The Shifflet's
shiffty@...
Aug 17, 2002 7:32 pm
1364
Hi Tony, Contrary to common belief column bleed is usually not simply caused by volatility of the phase. Bleed is caused by the following in descending order: ...
Rob Wohleb
WOHLEB@...
Aug 19, 2002 8:11 am
1365
I am interested in purchasing a new PDA detector to be connected with my existing Gilson make HPLC. Please suggest some good make detector and what all...
Bleed from commercial lots of phase may vary from batch to batch. This is due to the distribution of the molecular weight of the polymer. A considerable...
Hi Im just stuck with a little problem. Im currently doing some Reverse phase HPLC, with a 70%water:30%acetonitrile:1%acetic acid mobile phase, analysing...
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