Agilent 8453 uv vis

The total amount of phenolic compounds in propolis extracts was determined spectrophotometrically using the Folin-Ciocalteu method [16 (link)] with slight modifications. Every investigated extract (0.5 ml) was mixed with 2 N 0.5 ml of Folin-Ciocalteu reagent for 6 min. After the addition of 1.5 ml 20% Na₂CO₃, the volume was made up to 10 ml with corresponding extraction solvents, followed by incubation for 2 h at room temperature. Absorbance of the mixture was measured at 765 nm using spectrophotometer Agilent 8453 UV-Vis (Agilent Technologies Inc., Santa Clara, USA). Total phenolic compounds content was calculated from the calibration curve of p-coumaric acid and expressed as milligram of p-coumaric acid equivalents per ml of propolis extract.

Absorbance measurement was performed by using an Agilent 8453 UV-Vis (Agilent technologies, Santa Clara, CA, USA). After mixing 1% (v/v) photoabsorbers of various colors (Red, Orange, Yellow, Green, Blue, Purple, and Pink) in DPBS with 0.5% (w/v) LAP, the samples were placed in a cuvette and measured. The blank group did not contain any photoabsorber.