Masaru Shiraki

An Improved Method Fòr Extraction, Partial Purification, Separation and Isolation of Chlorophyll from Spinach Leaves

Abstract Powdered sugar column chromatographic separation and isolation of chlorophyll were studied. A wet column was employed using a Pharmacia R25 chromatographic tube connected, through a UV monitor, to a fraction collector. Chlorophyll extracted from spinach leaves with acetone was selectively precipitated with dioxane and water, and then was washed with 80% (v/v) aqueous methanol. Use of the further purified chlorophyll as a starting material for chromatographic separation and isolation of chlorophyll, made column chromatographic procedures become extremely effective and easier. Thin-layer chromatographic and high-performance liquid chromatographic tests revealed that chlorophyll preparations in this study did not contain any other photosynthetic pigments and their degradation products.

Photoelectric Effects in Organic Diodes

Photovoltaic behavior of the merocyanine dye family with a rhodanine ring has been systematically studied by employing eight different derivatives in the diode structure Al/evaporated dye/Ag. Each dye film behaves like a p-type semiconductor with a rectifying barrier at Al interface and an Ohmic contact at Ag electrode. The open circuit photovoltage as high as Voc1.5 V was observed for one of the derivatives, while the fill factor remained f.f.0.25 in all cases. The chemical stability of the dye molecules during and after evaporation is also discussed on the basis of the results obtained by the thin-layer chromatography.

An Improved Method for the Preparation of Chlorophyll by Means of Column Chromatography with Sepharose CL-6B

Abstract An improved method for the preparation of chlorophyll “a” and chlorophyll “b” from fresh spinach leaves by means of the column chromatography with Sepharose CL-6B has been developed. A good separation of the green pigments was attained on the column (φ25 × 163 mm) with a mixed solvent program of 2, 3, 10 and 20 % 2-propanol in hexane.

An improved method for the rapid and easy separation of leaf pigments and their derivatives by thin-layer chromatography

Abstract A thin-layer chromatographic method for the separation and identification of leaf pigments and their degradation products on commercial silica gel layer has been developed to give a tool to examine the purity of chlorophyll preparations and the chemical stability of chlorophyll molecules during the course of the chlorophyll preparation. It has been confirmed that the developing solvent system (isopentane:tert-butyl alcohol:acetone = 90:5:5, v/v/v) is quite useful to separate the photosynthetic pigments and their degradation products which were commonly found during the course of in vitro chlorophyll studies.

Preparation of chlorophyll-a and chlorophyll-b by means of column chromatography with Sephasorb HP Ultrafine

Chlorophyll-a and chlorophyll-b were prepared from spinach leaves by means of column chromatography with Sephasorb HP Ultrafine.