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By PeeChenMin on Thursday, August 12, 2004 - 02:42 am:
The following is the chromatographic procedure that I use in my method validation for Dequalinium Chloride Tablet (reference: BP 2002)
—a stainless steel column 0.15 m long and 4.6 mm in internal diameter packed with an end-capped octadecylsilyl silica gel for chromatography R,
—flow rate of 1.0 ml/min
-mobile phase:
A : dissolve 2 g of sodium hexanesulphonate in 300 ml of water. Add 1ml TEA and Adjust to pH 4.0 with acetic acid, dilute to 1L with UHQ water (66%)
B : Acetonitrite (34%)
—as detector a spectrophotometer set at 245 nm.
I am able to pass linearity, but failed in accuracy with result arround 106%. Any advice? Should I change the Mobile phase to avoid reaction from taking place?
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By Uwe Neue on Sunday, August 15, 2004 - 07:13 pm:
I do not see any reaction with your mobile phase that could cause a problem. Therefore I do not advise to change the mobile phase composition. I would look somewhere else for the source of the problem, from sample solvent evaporation to measurement error (how do you quantitate?) etc.
The following is the chromatographic procedure that I use in my method validation for Dequalinium Chloride Tablet (reference: BP 2002)
—a stainless steel column 0.15 m long and 4.6 mm in internal diameter packed with an end-capped octadecylsilyl silica gel for chromatography R,
—flow rate of 1.0 ml/min
-mobile phase:
A : dissolve 2 g of sodium hexanesulphonate in 300 ml of water. Add 1ml TEA and Adjust to pH 4.0 with acetic acid, dilute to 1L with UHQ water (66%)
B : Acetonitrite (34%)
—as detector a spectrophotometer set at 245 nm.
I am able to pass linearity, but failed in accuracy with result arround 106%. Any advice? Should I change the Mobile phase to avoid reaction from taking place?
-------------------------------------------------------------------------------------------------------
By Uwe Neue on Sunday, August 15, 2004 - 07:13 pm:
I do not see any reaction with your mobile phase that could cause a problem. Therefore I do not advise to change the mobile phase composition. I would look somewhere else for the source of the problem, from sample solvent evaporation to measurement error (how do you quantitate?) etc.
