Because there is not enough of the chemical, petroleum ether is used instead. As a result make up suck 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 is soluble in petroleum.
Because of the chemical is not enough. Petroleum ether is used instead. The absorbance measured is negative due to the chlorophyll insoluble in petroleum.