Due to insufficient Chemical Petroleum additives instead of using ether. As a result, the values are negative values light suck because the chlorophyll does not like soluble in petroleum.
Since the chemical is not enough So instead of using petroleum ether As a result, the absorbance is negative. Because chlorophyll not soluble in petroleum.
Because of chemical is not enough. Petroleum is used instead of the ether. Reduced absorption were negative. Since chlorophyll like dissolved in petroleum.