How is caffeine identified in HPLC?
A simple HPLC-UV method was developed and validated for the determination of Caffeine content in tea and coffee samples of different local brands commercially available at Kathmandu and Kaski, Nepal. The peak response time for caffeine was observed at 2.66 minutes using UV detector set at 275 nm.
Why caffeine is used for HPLC?
If you mean the use of caffeine to check UV wavelength accuracy, lots of chromatographers prefer to use it over holmium oxide filters (or use it in addition to) because caffeine has both a local min & max in the UV range that’s at least close to the wavelengths commonly used on a daily basis.
Could an ion exchange column be used for the determination of caffeine?
Ion Exchange Method for Determination of Caffeine in Presence of Antipyrine and Phenacetin* After evaporation of the chloroform, the remaining residue containing caffeine and antipyrine is dissolved in water and passed through an ion exchange column filled with a resin in the ferric iron form.
How does ion exchange HPLC work?
Ion exchange (IEX) chromatography is a technique that is commonly used in biomolecule purification. It involves the separation of molecules on the basis of their charge. In anion exchange the stationary phase is positively charged whilst in cation exchange it is negatively charged.
How do you test for caffeine content?
Many companies measure caffeine in their beverages. They use a method called ultraviolet spectroscopy, Max explains. It measures how much ultraviolet light — light close to violet, but wavelengths that people cannot see — is absorbed by different chemicals.
What is the retention time for caffeine in HPLC?
Decaffeinated coffee must contain less than 0.1 % caffeine2. In the European Union, only beverages that do not typically contain caffeine, for example energy drinks, must be labeled with the amount of caffeine the beverages contain.
What is caffeine soluble in?
Caffeine is soluble on both water and alcohols; however, it is more soluble in alcohols than in water. Therefore, alcohols can be used to extract caffeine from coffee solution in water. For this activity, rubbing alcohol will be used as a solvent to extract caffeine.
How do you elute protein from ion exchange?
Retained proteins are eluted from the column by applying a modified buffer. Elution is most commonly achieved by gradually increasing ionic strength of the buffer via salt gradient, and proteins are eluted in order of increasing their net charges.
How do you make a standard solution of caffeine?
A 9942 mg/L stock standard solution of caffeine was prepared by dissolving 0.5 g of standard caffeine with 40 g of distilled water and diluted to final weight of 50.29 g in 100 mL volumetric flask.