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Questions related from Carlos Ezquer
Hi. I am working now with a DIONEX ICS-3000 HPLC system. I run a sequency about 1000 samples and when 800 samples aprox were analyzed pump stops and a message appears "Drive Current too large....
08 August 2017 5,868 27 View
Hi. I am developing an analytical method based on the quantification of mofetil mycophenolate (MMP) and mycophenolic acid (MPA). For this purpose HPLC with a reversed phase stionary phase column...
07 July 2017 2,231 6 View
Hi everyone. I'm trying to implement a new analytical method based on treatment biological samples (plasma, serum and urine) prior to analysis by RPLC (ODS column) in order to quantify...
12 December 2016 5,770 4 View
Hi. Ususally, OPA is used as a fluorogenic reagent for compounds with amino functional groups. Could I use OPA derivatizing reagent and use in UV detection. I read bibliography and frequently...
06 June 2016 1,171 3 View
Hi. I am trying to develop a new analytical method by LC. Mi matrix is intraperitoneal fluid. I´ve read some articles and for the development of the method validation some authors use water as a...
03 March 2016 4,161 3 View
How do you make experimental procedures to determine recovery in an analytical procedure? How do you calculate it? Please, put an example about your experimental procedures in case you use...
04 April 2015 2,168 5 View
Hi everyone. I am trying to develope an analytical method by HPLC based on reverse phase separation (C18 column) for determine a drug in a oftalmic presentation. The problem is that in this...
02 February 2015 1,877 6 View
I´ve been reading about peak tailing, loss of resolution and peak broadening in reversed phase columns and some authors explains that heavy metals can produce peak tailing on C18 columns. Any body...
12 December 2014 3,610 1 View
A colleague of mine is trying to develop a derivatization reaction to determine the amount of lenalidomide in rat plasma samples by LC coupled with fluorescence detection with the aim to develop...
06 June 2014 8,001 7 View
I'm studying the new technology of separation based on HILIC columns, but I don't understand the difference between normal phase chromatography and HILIC. It seems to me to be the same separation...
06 June 2014 9,376 5 View
I am developing new methods to determine hidrophilic compounds and I want to introduce a new method of separation based on hidrophilic interaction liquid chromatography in my thesis. This is a...
05 May 2014 7,234 4 View
I have seen that in many articles about development of LC analytic methods, triethilamine base is used in the aqueous phase. Please, can anyone explain the way it is used? I would like to know the...
04 April 2014 3,136 8 View
I'm developing an LC method to determine meropenem in patients' blood samples. Actually I'm using a mobile phase composed by 8% of ACN and an aqueous phase composed of 0.03 M of KH2PO4 adjusted to...
04 April 2014 6,482 50 View
I work in the area of bioanalytical determinations using HPLC coupled with UV or FLD detection. I would like to know about quick sample purification methods you can use to work with human plasma,...
03 March 2014 3,917 15 View
I'm trying to develop an HPLC method to determine MEROPENEM concentration in blood samples. A strange phenomenon has happened on preliminary testing to determine retention times of meropenem. I´m...
02 February 2014 3,124 16 View
