Application of the Shpol'skii effect to quantitative analysis of monomethylphenanthrene isomers

Improvement of Spectrophotometric Method for the Determination of Atrazine in Contaminated Water by Inducing of Mannich Reaction

“…C 0 is determined by the negative intercept of the curve with the abscissa axis (Muel & Lacroix, 1960;Rima, Lamotte & Joussot-Dubien, 1982).…”

“…Dechlorinated atrazine was added as an internal standard for the calibration of the measurement (Muel & Lacroix, 1960;Rima, Lamotte, & Joussot-Dubien, 1982). Determination of the pH was done using a Mettler Toledo (OH, USA) pH-meter.…”

Spectrofluorometric and high-performance liquid chromatographic determination of all-rac-α-tocopheryl acetate in virgin olive oil

“…C add is the known added concentration. The concentration C 0 is determined by the negative intercept of the extrapolated line with the x-axis (Muel and Lacroix, 1960;Rima et al, 1982). It is noted that this method requires a calibration curve for each sample.…”

“…A standard addition method (Muel and Lacroix, 1960;Rima et al, 1982) was used to calibrate all-rac-a-tocopheryl acetate contents in olive oils. The standard was all-rac-a-tocopheryl acetate added in olive oil.…”

High-performance liquid chromatographic and spectrofluorometric determination of α-tocopherol in a natural plant: Ferula hermonis (Zalooh root)

“…Moreover, the fluorescence spectrum of a-tocopherol extract of Zalooh, extracted following a chromatographic column, is examined on a spectrofluorophotometer at 292 nm excitation and 328 nm emission wavelength, and the amount of a-tocopherol present is dosed according to the internal addition method (Rima et al, 1982). We finally note that for the extraction of tocopherols, and before the HPLC or any other analysis, saponification is needed for samples high in fat in order to remove the fatty acids in excess (which is the case for Zalooh).…”