radio-carbon dating -- Method for determining the age of an organic substance by measuring the amount of the carbon isotope, carbon-14, remaining in the substance; useful for determining ages in the range of 500 to 70,000 years.
Fourier Transform Infrared Spectroscopy analyses the composition of a substance by measuring how much infrared energy is absorbed by different molecules, thereby enabling the molecules present to be determined.
Some acids are stronger than others, and in 1909, Sørensen proposed that we could quanitify how acidic or alkaline a substance was by measuring its concentration of hydrogen ions.
The fire retarding performance of 28 different inorganic chemical substances was tested by measuring the relative particle fire hazard properties of Pinus halepensis needles treated with these chemicals.
Volumetric analysis, any method of quantitative chemical analysis in which the amount of a substance is determined by measuring the volume that it occupies or, in broader usage, the volume of a second substance that combines with the first in known proportions, more correctly called titrimetric analysis (see titration).
The three age groups were treated with P. betle, C. vulgaris and TRF for 24 hours to evaluate the protective effect of these substances against cellular ageing, by measuring the activity of antioxidant enzymes.
Since peroxynitrite is formed by the interaction of superoxide and NO, we next measured the generation of the latter two substances along with [Ca2+]i mobilization by measuring dihydroethidium (DHE, a fluorescent indicator of superoxide), and diaminofluorescein-2 diacetate (DAF-2, an indicator of NO) fluorescence, respectively.
Because 4-nitrophenol which will be generated from substrates by enzymatic hydrolysis is a chromogenic substance, enzyme activities were assayed by measuring absorbance at 420 nm by UV-2550 Shimadzuhotometer (Shimadzu, Kyoto, Japan).
Oxidized LDL were analyzed by measuring thiobarbituric reactive substances (TBARS, 30 40 μmol/g protein) and EO6-reactive phospholipid oxidation products.
MDA content was assessed using thiobarbituric acid reactive substances assay (Jiancheng Bioengineering, Nanjing, China) by measuring the absorbance value at wavelength of 532 nm.
