I recently failed to use TiOSO4 for H2O2 detection. The samples are extracted with acetone from homogenized tumor samples. TiOSO4 was dissolved in 2M H2SO4 and then mixed with acetone extracts with 1:1 (v/v) ratio. Everytime when I mixed the two, large amount of white/yellow precipitation formed and I had to centrifuge down to test UV-Vis absorption of supernatant. However the interference is still high to the typical peak of Ti(IV)(O2)(OH)2 at 405 nm. Does anyone have a better practical protocol or should I use fluorescence dye for H2O2 detection? Thanks.
Dear Sir. Concerning your issue about the protocol for H2O2 detection with fluorescence dye TiOSO4. Measurements of hydrogen peroxide formed in plasma treated water were performed by titanium sulfate colorimetric method... The intense yellow color is formed when an acidic solution of titanyl ions are mixed with H2O2. The method is specific to H2O2 and there are no interferences from other compounds present in water, while working under strong acidic conditions following the modified procedure of Satterfield and Bonnel [Anal. Chem. 1955]. The Lambert-Beer’s law is followed and the yellow color intensity is proportional to the H2O2 concentration giving a linear relationship. The molar extinction coefficient determined in our laboratory from the slope of the calibration plot at the wavelength [of] 407nm was e=6.89 x 10^2 L/mol-cm. The method is independent of the pH since the measurement of H2O2 is carried out in strong acidic solution of sulfuric acid (dilute 1:1). In the presence of nitrites, a solution of sodium azide was added to the samples with H2O2 prior to mixing with titanium reagent to eliminate decomposition of H2O2 by nitrites under acidic conditions. With sodium azide, nitrites are reduced into molecular nitrogen under acidic conditions." I think the following below links may help you in your analysis:
http://www.graveslab.org/lab-resources/procedures/peroxide-h2o2-quantification
http://cdmbuntu.lib.utah.edu/utils/getfile/collection/etd3/id/3173/filename/3175.pdf
https://arxiv.org/ftp/arxiv/papers/1604/1604.08803.pdf
Thanks
I used Titanium(III)sulfate Ti2(SO4)3 (0.1% in diluted sulfuric acid) instead of Titanyl sulfate TiOSO4 and it worked very well.
best regards
Mohammad
Mohamad Issaoui Hi Mohammad did you use acetone to extract H2O2 from biological samples?@
Acetone has been shown to interfere with the TiOSO4 quantification method, please see https://doi.org/10.1021/ac60103a042. Also white/yellow precipitate might mean your Ti hydrolysed, which would point towards your pH not being low enough.
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