A simple 96-well microplate method for estimation of total polyphenolic content in seaweeds

Seaweed polyphenols are potent antioxidants and have also been shown to have α-glucosidase inhibiting activity. In our continuous efforts to develop new marine-based nutraceuticals and functional food ingredients, we have investigated many algal species collected on the Atlantic coast of Canada. A simple method for estimating the total polyphenol content in seaweeds and their extracts was developed based on the classic Folin-Ciocalteau colorimetric reaction. By using the 96-well microplate and a microplate reader, this new method saves experimental time, significantly reduces the amount of sample required, handles large number of samples in one experiment, and also improves the repeatability of the results.

A number of algal samples collected on the seashore of Nova Scotia, Canada, were analyzed for their levels of polyphenol content using this microplate-based method. The antioxidant activity of these samples was also assessed by using DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The results showed that there is a strong correlation between the total polyphenol content and the potency of antioxidant effect.

Investigating effects of potential excursions and pH variations on cathodic protection using new electrochemical testing cells

Excursion from safe cathodic protection (CP) potentials occurs on buried steel pipelines due to various forms of electrical interferences such as stray currents. Variations in pH can also occur over some pipeline sections such as seashore and river crossing pipes. Currently, the exact effects of potential excursion and the pH on CP efficiency have not been sufficiently quantified preliminary due to difficulties in measuring these effects. In this work, these effects have been investigated using electrochemical cells designed to mimic the high resistivity and pH conditions observable over underground steel pipes, including a new electrochemical cell that has been designed to facilitate the effective simulation and control of pH, potential excursion and other CP testing parameters. The pH has been shown to be a key factor affecting the patterns of corrosion and CP efficiency. Localised corrosion has been found to be the dominating form of corrosion under potential excursions conditions.