By Anonymous on Monday, December 9, 2002 - 06:20 am:
Does someone know about an HPLC analytical method of azithromycin using UV-VIS detector?
By deST on Monday, December 9, 2002 - 09:56 am:
HPLC Method for Azitromycin:
Detector: 210 nm
Column: C-8 (4.6 x 150 mm 5um)
Flow Rate: 1.0 mL/min
Injection Volume: 20 uL
Mobile Phase: (MeOH:H2KPO4 0.0335M) (80:20)
Diluent: (MeOH:H2KPO4) 0.0335M (50:50)
(H2KPO4 0.0335M: 4.55g/1L water pH 7.5)
Sample = Standard: 60 mg/100 mL Diluent
Do you need a chromatogram?
Best regards
By Anonymous on Monday, December 9, 2002 - 11:44 pm:
Thank you very much deST !
I would be happy to have a chromatogram.
3 questions: 1) can I use a C-18 column (4.6 x 150 mm 5um)?
2) is there no pH adjustment needed for the Mobile Phase?
3) is there an official reference for this method?
Best regards.
By deST on Tuesday, December 10, 2002 - 01:35 am:
Hello Anon;
1) You can use your C-18 column, but the analytical run will be highest
2) Yes, remember: H2KPO4 pH 7.5
3) No. It is internal development
Best Regardds
By Anonymous on Tuesday, December 10, 2002 - 03:44 am:
well deST, thank you very much, again.
Best regards
Anon.
By Anonymous on Sunday, December 15, 2002 - 06:14 pm:
These methods are quite often not selective for this molecule. Is your application for assay or related compounds? Also be careful of the placebo interference. EC detectors were incorporated into the USP for a good reason. That reason is selectivity.
By Anonymous on Tuesday, December 17, 2002 - 04:34 am:
Hello Anonymous,
My application is for an assay,
and I don't (and won't) have an EC detector.
By Anonymous on Sunday, May 2, 2004 - 07:00 am:
I have tried the C-18 column but get low values. However, the problem is that in presence of citric acid which is part of my formulation the peak of azithromycin merges with that of citric acid and results vary. Can you help?
By Anonymous on Sunday, May 2, 2004 - 11:05 am:
What is the pH of your 33.5 mM H2KPO4 solution?
By Einar Pontén - SeQuant AB on Sunday, May 2, 2004 - 02:21 pm:
Question to deST. Have your ever tested to use acetonitrile instead of methanol? What brandname is your C8 column? It seems a little bit strange that this quite hydrophilic compound require 80% MeOH or am I wrong about its properties? The retention on a C18 is low (see above).
By gulseren on Monday, May 17, 2004 - 12:26 pm:
I must check the presence of citrinin in a methanol soluable but highly hydrophobic monascus dyes. There is HPLC at lab with C18 column. Is it possible to use this column with such a sample?