My problem now is when I analyze turmeric extracts (mostly curcuminoids) with HPLC, the results show 3 peaks of BDMC, DMC and curcumin. However, with spectrophotometer results, it just showed the absorbance (combine all components). I would like to get data from every single components (BDMC, DMC and C) and make a comparison. It could be if I build up 3 different calibration for HPLC but I can not do the same thing with spectrophotometer (Because one abs value always combine all into one).
Thank you in advance for any answer or hint.
The two analytical tools offer different results. HPLC is obviously superior to spectrophotometric analysis depending on what you want. Read up the principles and applications of the two methods carefully before you initiate the analysis. Separate results of your fractions are a lot better than one one lumped result, or don't you think, but again depending on what your interest is.
Hi, for simultaneous determination of curcumin, DMC and BDMC, I think you should do it by HPLC or TLC. Yes, you should do 3 calibrations for each of compound. It is impossible to determine those compounds using spectrophotometer.
With best wishes, Gunawan
Hello, the HPLC shows the three peaks which are characteristic of the three compounds it is normal but on the other hand the spectrophotometer could not do the same thing because the UV spectrophotometer shows that the absorbance of a majority compound containing in the extracted at any maximum length, the other two compounds are linked by a bond to the majority compounds. This is why we cannot have the absorbance of the two other containing compounds in the mixture.
In HPLC there is the affinity between the constituents of the sample to be analyzed and the two phases: the mobile phase and the stationary phase. This is why the retention of its three compounds is done in different places on the other hand in spectrophotometer we can also say that the three compounds containing in the extract have almost identical chromophores hence the corresponding abundance is that of the Chromophore . This is why we can only have one absorbance.
HPLC consists of a UV detector that works similarly to a UV spectrophotometer. The main difference is that in HPLC, the UV detector detects each compound after separated by the HPLC column which is part of chromatography. If the separation went well, then you get separated peaks (3 peaks in your extract: BDMC, DMC, and curcumin). However, in UV spectrophotometer (UV-Vis), you run one sample of extract in a cuvette containing all the compounds and detects the absorption (peak) at a certain range of the wavelengths (maybe 200 - 650 nm). The point is the compounds are not separated in the UV spectrophotometer, hence the peaks are overlapped, not to mention that they contain similar structures and chromophores. My suggestion is by using HPLC, the results would be favorable, but if you have to compare the results with a UV spectrophotometer, then finding each maximum wavelength may be a help to get the equivalent value.
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