For precision study, 0.5 and 1.0 mg P L1 was evaluated for five
replicates, the percent of relative standard deviation (%RSD) values
were 0.95 and 2.1%, respectively. The inter-day precision was also
obtained, %RSD values were 1.0 and 1.5%, respectively. The method
had a sample throughput about 40 samples h1
. The percent of
relative error (%RE) was evaluated by analyzing known concentration
of standard phosphorus of 0.3 and 0.8 mg P L1 for three replicates
using the calibration graph stored in the mobile phone. The %RE of
3.8% (for 0.3 mg P L1
) and 4.7% (for 0.8 mg P L1
) were obtained.