Evaluating the use of 3'-(p-Aminophenyl) fluorescein for determining the formation of highly reactive oxygen species in particle suspensions

摘要

Background: Given the importance of highly reactive oxygen species (hROS) as reactants in awide range of biological, photochemical, and environmental systems there is an interest indetection and quantification of these species. The extreme reactivity of the hROS, which includeshydroxyl radicals, presents an analytical challenge. 3'-(p-Aminophenyl) fluorescein (APF) is arelatively new probe used for measuring hROS. Here, we further evaluate the use of APF as amethod for the detection of hydroxyl radicals in particle suspensions.Results: Particle-generated hROS can be quantified with an estimated detection limit of 50 nM.Measurements of hROS in two National Institute of Standards and Technology (NIST 2709 and2710) soil suspensions and a pyrite suspension show non-linear particle dose-response curves forhROS generation. APF can also be used in solutions containing no dissolved molecular oxygen (O2)to determine the role of O2 in the formation of hROS. Results confirm that O2 is mechanisticallyimportant in the formation of hROS by dissolved ferrous iron and in pyrite suspensions.Conclusion: Given the non-linear dose-response curves for particle generation of hROS, werecommend using several particle loadings in experiments aimed to compare particles for theirhROS generation potential. The method presented here is specific to hROS and simple to perform.The analysis can be conducted in mobile labs as only basic laboratory equipment is required.