Keerthi Bandara Jayasundera

11 Questions 23 Answers 0 Followers

Questions related from Keerthi Bandara Jayasundera

Can 0.1% ammonium hydroxide damage HILIC column?

In my LC-MS experiment, I am utilizing an Agilent Polaris NH2 column to separate a mixture of glucose, fructose, and sucrose. I am using water and acetonitrile as A and B mobile phases...

27 March 2024 8,860 4 View

Why polymer like peaks with C30 column always?

I am using a C30 column for carotenoid analysis. I bought the column recently and using it for the first time. When I use the column in LC-MS scan mode, I clearly see the UV-Vis peaks for my...

09 June 2023 2,322 2 View

What is the possible peak at m/z = 535.8 for lycopene?

I am analyzing Lycopene using LC-MS. I use a C18 column and my mobile phase is Methanol: MTBE = 95:5. I use an Agilent Ultivo QQQ mass spectrometer with APCI negative ion mode. I see the precursor...

08 May 2023 490 0 View

What does "defined levels are outside of dataset range" mean in 2D NMR?

I am running an HMBC experiment on a Bruker 300 mHz instrument. I set up the experiment following the steps given in TopSpin guide book. Everything happens fine but when I try to open the spectrum...

10 March 2023 5,264 4 View

What is a suitable solid phase extraction method for fatty acid methyl esters?

I need to concentrate some fatty acid methyl esters in a cell culture medium to separate and isolate them using Prep-HPLC. What type of solid phase extraction would be suitable to concentrate...

03 March 2023 9,487 0 View

Is it possible to use the same column for HPLC and LC-MS?

I used the following column for an HPLC separation; C18 4.6 x 250 mm, 5 um, 120 Ao. I used methanol and acetonitrile as mobile phases. Now I have to do LC-MS for the same samples. I am wondering...

20 December 2022 1,867 6 View

What are some possible substrates that can be used to test laccase activity?

I want to know some cheap, easily available compounds that can be used as substrates to detect laccase activity instead of ABTS using UV-Vis spectrometer.

28 April 2021 225 3 View

Is there any experimental method to determine carbon nano tube - polymer bonding in a composite?

I have seen that in CNT -polymer composites the bonding strength (van der waals, covalent etc) has been predicted by simulation. Is there any method to experimentally measure bonding strength or...

22 November 2017 9,525 3 View

Do lead(ii) ions adsorb on filter paper?

For some adsorption experiment we are using 10 ppm Pb(ii) solution. However Pb(ii) adsorb onto the filter paper significantly making it difficult to get a reliable reading from AAS. Does anybody...

18 October 2017 2,164 3 View

What is a suitable vacuum pump for a solid phase extraction manifold?

What would be a suitable vacuum pump for a solid phase extraction manifold (VAC ELUT SPS 24, 10 X 75MM RACK (from Agilent).

15 February 2017 8,123 5 View

What is a simple reaction to connect a hydroxyl group to another molecule?

I need to connect an -OH group to another molecule in one or two steps without harsh reaction conditions, easiest way seems like making an ester. But I think esters get hydrolyzed easily. Are...

23 October 2015 6,043 6 View