| 
   
  |  | Actual concentration (µg mL-1)
 | Intra-day (n=5) | Inter-day* (n=5) |  
  | Foundconcentration (µg mL-1)
 | RSD (%) | Foundconcentration (µg mL-1)
 | RSD (%) |  
  |  | 5.00 | 4.96 | 0.50 | 4.95 | 0.54 |  
  | SAX | 50.00 | 50.10 | 0.18 | 49.92 | 0.22 |  
  |  | 100.00 | 99.62 | 1.07 | 98.86 | 0.94 |  
  | MET | 2.5025.0050.00 | 2.4924.8949.88 | 1.520.120.78 | 2.5225.0150.12 | 0.270.481.03 |  | 
  
 | *Results of five different days | 
  
 | Table 4: Results from intra-day and inter-day precision experiments for SAX and MET. |