Because there is not enough Chemical Petroleum additives instead of using ether. As a result, suck up the light temple has been negative since the chlorophyll does not dissolve in petroleum.
The chemical is not enough So instead of using petroleum ether As a result, the absorbance is measured to have a negative value. Because chlorophyll insoluble in petroleum.
Because of the chemical is not enough. Petroleum is used instead of the ether. Result the absorbance measured is negative. Since chlorophyll insoluble in petroleum.