Caffeine having different wavelents it having 2 maximas and 1 minima. 1st maxima is 205nm 2nd maxima is 273nm minima is 245nm and it is primary reference standard and also suggested in pharmacopiea.
-Rajesh,Orchid
Caffeine responds in 3 wavelength regions i.e
196 - 208nm in which caffeine maxima at 203±2nm
240 - 248nm in which caffeine minima at 244±2nm
270 - 278nm in which caffeine maxima at 273±2nm
So it covers the operation range of HPLC UV detector to perform wavelength accuracy.
Apart from this Caffeine elutes in approx 2 min when using any C18 column which helps in reducing run time.
That s the caffeine is preferred than any other standards for HPLC calibration
K S Badrinath
Caffeineis dule absorbance,it gives multiwavelength responds like 205,245,273.
It is very stable(3 days at room temp.) ,it is having multi wavelength like 2 maxi ma (205 ,273 nm and minima(245nm) and cheap cost.
Erbium has a strong absorption in uv and visible range, It is used in HPlc calibration for the wavelength accuracy verification of the PDA detector.
propyl paraben being a stable compound with reproducible chromatographic parameters used as a internal standard for the calibration of the HPLC systems
Caffeine having different wavelents it having 2 maximas and 1 minima. 1st maxima is 205nm 2nd maxima is 273nm minima is 245nm and it is primary reference standard and also suggested in pharmacopiea. -Rajesh,Orchid
Caffeine having different wavelents it having 2 maximas and 1 minima. 1st maxima is 205nm 2nd maxima is 273nm minima is 245nm and it is primary reference standard and also suggested in pharmacopiea. -Rajesh,Orchid
higly unretainable and has high absorption at 260 nm
higly unretainable and has high absorption at 260 nm
it is retained to a lesser extent....has dual wavelength detection (245nm, 350nm) and gives a sharp and consistent peak.
NP-HPLC is "Normal Phase" HPLC, wherein the solvents used are less polar than the substrate in the HPLC column (e.g. using hexane or dichloromethane with a silica HPLC column). RP-HPLC is "Reverse-Phase" HPLC, wherein the solvents used are more polar than the substrate in the HPLC column (e.g. using Water and Methanol with a octadecylsilane (ODS or C18) column).
1. Flow rate 2. Temp. of column 3. Detector function 4. Resolution
Caffeineis dule absorbance,it gives multiwavelength responds like 205,245,273.
You need to specify the kind of calibration you are asking, to get the right answer
i dnt know