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Questions related to Liquid Chromatography
I have run 300 uM of tryptophan in isocratic 50% methanol with 40 mM sodium citrate buffer pH 2.25, 400 uM SDS in a 40 min run at 35 degree and absorbance at 280 nm. During two reps the RT changed...
28 March 2017 8,030 7 View
I'm trying to to purify protein sample using agilent HPLC system with C18 column. The moment I load sample and start program within few minutes the desired protein elute out along with solvent...
20 March 2017 5,989 9 View
Hi everybody. I was trying to analyse Ivermectin in a pharmaceutical product, but when I ran the standard it does not appear any peak (I'm using the USP 39 method for ivermectin). I tried to...
03 March 2017 287 4 View
Channel is wide with width 6 mm, height 0.4 mm, length 60 mm. I want to achieve flow rates from 1 ul/min to 25 ul/min in my system. Flow rates below say 100 ul/min (using syringe pump with 2 ml...
03 March 2017 5,815 5 View
03 March 2017 1,236 10 View
03 March 2017 4,242 8 View
LC-MS system comprised of QTrap3200 and a Shamidzu HPLC (Autosampler model is SIL-20A). The needle is not going into the well instead going in between two wells and not picking up the sample....
24 February 2017 1,569 4 View
Respected Sir, I am doing method development.pKa of drug is 10.24. Column I am using YMC Pack Pro C18 250 mm in length and 3 micrometer in size. on one run of 100 ml of mobile phase pressure is...
06 February 2017 5,499 5 View
02 February 2017 6,666 6 View
I have recently started working on top-down proteomics and while working obtains many chromatograms of envelope shapes. Even the software has the option to deconvolute and identifies the molecular...
02 February 2017 6,839 2 View
In a separation of a basic drug analyte from its impurity using strong cation exchange chromatography (HPLC), using 150 mM of ammonium dihydrogen phosphate at pH 3 and flow of 1.4 ml/min, the...
24 January 2017 2,676 5 View
Worked on 2 separate HPLC methods, first one uses 100% of 5mM sodium phosphate pH6.8 and aqueous compatible HPLC column and column oven temperature of 40C. Get resolution between imipenem...
04 January 2017 6,378 5 View
01 January 2017 8,162 6 View
We tried a Luna C18 260 x 4.6 but analysis time is too long and separation is not good for 6 amino acids. We are looking for a column which a researcher has worked with and is satisfied and not...
01 January 2017 2,858 9 View
Is Inverse Liquid Chromatography evaluated? Is surface energy measured by IGC enough or are other values as Ka, Kb considered too? Do you evaluate also Hansen Solubility Parameters? Looking...
01 January 2017 6,783 1 View
azo dyes are recalcitrant and tough. They have high molecular weight and require both anoxic and aerobic conditions to be degraded totally. columns to be used in liquid chromatography mass...
01 January 2017 3,330 2 View
I am working on Ir complexes, which have 3+ charged. I am struggling on the purification step. I purified my complexes using SP Sephadex C-25. I prepared the sephadex media in 0.2 M NaCl for 24...
12 December 2016 7,257 8 View
I have the Excel file of the LC data, and it has more than 30 peaks on it. I do not know how to get the average peak capacity from it since we have 30 peaks. Do I need to calculated each number...
12 December 2016 5,058 3 View
01 December 2016 3,751 7 View
Hello, We have HPLC Agilent 1260 the problem is that the pressure bcom very low when we use the gradient mode (The addition of water during the time with Acetonitrile) causes this problem of pressure.
21 November 2016 5,682 7 View
I am just trying to run a CapLC coupled to a Q-tof. In isocratic mode it works fine, however once a single gradient step is set this message appears "Ternary gradient detected in auxiliary...
11 November 2016 5,251 3 View
Can i purify the Fucoidan through FPLC instruments.
11 November 2016 1,804 4 View
what difference between Gas chromatography–mass spectrometry,GC- MS MS AND Liquid chromatography–mass spectrometry?
11 November 2016 9,816 2 View
I need to perform offline fractionation by HILIC. I have done offline fractionation using disposable RP columns (I have used home made columns with oligo R3 material, but Thermo sells disposable...
07 November 2016 4,908 1 View