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Hello,
I am carrying out analysis of amodiaquine using a method from D J Bell
mobile phase - water:methanol:triethylamine(83:16:1)
calibration ranges : 200-1000ng/ml
drug:amodiaquine,desethlyamodiaquine,qinidine (IS)
Working solution - 20mcg/ml
Chromatography instrument - Acta make
The neat injections of the individual drug in the calibration ranges
(e.g 10 microlitres of working soln to 1ml with mobile phase)
produced no curve.There were however curves (small) when 100
microlitres of the working solution was neatly injected.
Can anybody tell me what is wrong?
Then, the recovery of the extraction method is low - 40-65%.
I need assistance of an extraction method that will give 80-90
recovery rate
Looking forward to your help
Muyiwa Adedeji
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The following message was posted to: PharmPK
Muyiwa: What is the column? what is the detection, what is the pH, temp
flrt? Do you get a response from the quinidine?
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The following message was posted to: PharmPK
Hello,
I do not know the exact reasons for your low recovery.
We did experience carry-over problem for desethylamodiaquine analysis.
The following paper has the method to solve the carry-over problem.
Robert L, et al., Drug metabolism and dispostion (2004), Vol 32,
647-660.
Thanks,
Limei
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he following message was posted to: PharmPK
According to his post, he doesn't have a carry over issue
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ed,
other information are:
The column is C18,the mobile phase (water/methanol/triethlyamine,
83/16/1% v/v) was adjusted to pH 2.2 with conc orthophosphoric acid.
Flow rate is 1.5ml/min
Detection at 340nm
Retention times (tR) of the drugs are Amodiaquine,AQm and Quinidine
are 10.99 min,8.7 min and 5.05 min repectively
However,on reconstituting the drug in the mobile phase to make up to
1ml (calibration range of 200-1000ng/ml),no peak was produced
Thanks
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The following message was posted to: PharmPK
These are basic question but be patient.
Did you notice anything about the solution when you mixed the drugs in
mobile phase?
Did the solvent front increase or decrease in mobile phase compared to
your
ordinary prep?
Has the column been used for anything else? If yes, can you try a fresh
column?
Have you looked at the signal at 254 nm?
Are you using a precolumn or guard column? If so is it the same
material as
the analytical column?
Are all preparations fresh?
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