Dear all,Back to the Top
We are developing the HPLC method for estimation of cortisol and 6-beta
hydroxy cortisol in urine. As cortisol and 6-beta hydroxy cortisol are
endogenous compounds, how can we get the blank urine without cortisol
and 6-beta hydroxy cortisol for method development and validation.
Thanks in advance,
Dear Jaya Sagar,Back to the Top
There has been a method proposed by Doppenschmitt et al to prepare
cortisol free serum samples. Referece is given below:
Simultaneous determination of tramcinolone acetonide and hydrocortisone
in human plasma by HPLC, S.A Doppenschmitt, B. Scheidel, F. Harrison, J.P.
Surmann, J of Chromatography B, 682 (1996) 79-88.
one more reference that might be helpful to you:
Simultaneous determination of glucocorticoids in plsma or urine by HPLC
with precolumn fluorimetric derivatization by 9-Anthroyl nitrile, Nobugito
Shibata, Taro Hayakawa, Kanji Takada, Nobuo Hoshino, Tokuzo Minouchi, Akira
Yamaji, J of chromatography B, 706 (1998) 191-199
Hope this helps, Good luck
Dear SagarBack to the Top
I think you can prepare a simulated urine artificially minus these
Dept. of Pharmaceutical Medicine
Ranbaxy CPU, Hamdard Univ.
Jaya,Back to the Top
What we have used is water as a surrogate matrix to run both
calibration and QC samples.
What you are looking for are variations (increase/decrease) from
baseline, absolute quantification is not necessary and each subject
acts as its own control.
Stefano Persiani, PhD
Director, Drug Metabolism and Pharmacokinetics
Rotta Research Laboratorium, spa
Via Valosa di Sopra, 7-9
20052 Monza (MI) ITALY
Tel +39 039 7390396
Fax +39 039 7390371
Dear Jayasagar gunduBack to the Top
You could try Amberlite XAD-2 columns reins to strip cortisol and
6-beta hydroxy cortisol.
Dr. Ibrahim Wasfi
Camel Racing Laboratory
P O BOX 253, Abu Dhabi
United Arab Emirates
Tel 00971 2 4092522
Fax 00971 2 4463470
Dear Jaya sagarBack to the Top
If any estimations like this are difficult and involves careful
planning of the experiments. One way of doing this is by estimating
blank urine levels and constant substracting the value from all the
time point concentrations will reasonably give the estimation to a
greater precision and accuracy. Spiking standards and Quality controls
will follow the same way of subraction. Also Method developed should be
sensitive enough to detect the levels. Using same subject blank for
spiking standards and QCs would result in greater accuracy. Any
comments are wellcome.
Akula Bapuji, P.hD
Group Leader- Bioanalytical(LCMSMS)
Ranabxy Research Labs.
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