Hello,
I have conducted a UV-Vis spectroscopy of Aniline in DDW which was showing two intense peaks at 230 (most intense) and 280nm. I am planning to conduct an experiment to detect the change in concentration of Aniline in a solution which also contains metal ions (from various salts like MgSO4, CaCl2, KH2PO4 etc.). On conducting a UV-Vis spectroscopy of the liquid media (without Aniline), I observed a sharp peak at 230nm which could be due to the presence of metal ions.
Thus, in a solution containing both Aniline and metal (when diluted to reduce the Aniline concentration) the overall intensity of the peak at 230nm does not change, however, the peak at 280nm changes significantly. The interference of the 230nm peak due to metal ions is not allowing the proper monitoring of the change in Aniline concentration.
Can the less intense peak at 280nm be observed to monitor change in Aniline concentration?
P.S.: Extraction of Aniline in an organic solvent could possibly solve the problem (either doing UV-Vis or HPLC), though in case I have to monitor the changes in a water system, what could be the best way to approach this situation.
You should choose 280 nm peak. It is generally not advisable to perform quantitative analysis in deep UV (in this case 230 nm). The reasons are generally solvent cutoff, cuvette transparency, interference from various UV absorbing species. Sample impurity could also play a part here. Also, you not necessary have to monitor at the peak you can monitor at the edges also.
Hello,
You can change wavelength to decrease background signal and increase selectivity, but if need high sensetivity, you can also think about derivatization. There are a lot of reagents, which could be suitible for you.
Best regards,
Azamat
Thank you Tuhin, Dr. Allan and Dr. Azamat for your answers. I will certainly consider the advice of making a calibration curve and see if there is any change in absorption due to the presence of cations. With this, I can also monitor the changes in the peak at 280nm.
Thank you again for providing your valuable comments.
- Badges
- Science method
- Similar topics
- Chemistry
- General Biochemistry
- Biochemical Techniques
- Analytical Chemistry