Table 2.
The concentrations and recoveries of CYA and FC in synthetic and natural water samples measured by IC and colorimetric methods (replicate ≥ 2).
| Method | Water matrix | Cyanuric acid (CYA) |
Free chlorine (FC) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Found (mg/L) | RSD (%) | Dosed (mg/L) | Recovery (%) | RSD (%) | Found (mg/L) | RSD (%) | Dosed (mg/L) | Recovery (%) | RSD (%) | ||
| IC method | Pure water 1 | < MDL | NA | 0.08 | 96 | 7.4 | < MDL | NA | 0.08 | 95 | 9.8 |
| Pure water 2 | < MDL | NA | 0.5 | 109 | 2.3 | < MDL | NA | 0.5 | 87 | 5.3 | |
| Pure water 3 | < MDL | NA | 1.0 | 96 | 3.0 | < MDL | NA | 1.0 | 109 | 1.3 | |
| Pure water 4 | < MDL | NA | 0.5 | 88 | 5.0 | < MDL | NA | 0.5 | 90 | 5.2 | |
| Pure water 5 | < MDL | NA | 0.1 | 109 | 7.7 | < MDL | NA | 0.01 | 112 | 9.1 | |
| Pure water 6 | < MDL | NA | 1.0 | 108 | 4.3 | < MDL | NA | 1.0 | 95 | 4.0 | |
| Pure water 7 | < MDL | NA | 1.0 | 99 | 7.1 | < MDL | NA | 5.0 | 95 | 2.1 | |
| Tap water 1 | < MDL | NA | 0.1 | 92 | 4.4 | 0.18 | 6.1 | 1.0 | 109 | 2.4 | |
| Tap water 2 | < MDL | NA | 1.0 | 98 | 6.1 | 0.15 | 4.9 | 5.0 | 104 | 5.6 | |
| Rain water 1 | < MDL | NA | 0.1 | 95 | 6.9 | < MDL | NA | 0.1 | 108 | 2.4 | |
| Rain water 2 | < MDL | NA | 1.0 | 95 | 4.2 | < MDL | NA | 10.0 | 95 | 6.1 | |
| Lake water1 | < MDL | NA | 0.1 | 99 | 1.7 | < MDL | NA | 0.5 | 98 | 2.1 | |
| Lake water2 | < MDL | NA | 1.0 | 101 | 4.5 | < MDL | NA | 5.0 | 106 | 2.7 | |
| River water1 | 0.04 | 2.5 | 0 | – | – | < MDL | NA | 0 | – | – | |
| River water2 | 0.03 | 3.4 | 0 | – | – | < MDL | NA | 0 | – | – | |
| Wastewater effluent | 0.23 | 3.2 | 0 | – | – | < MDL | NA | 0 | – | – | |
| Swimming pool water 1 | 12.68 | 2.6 | 0.5 | 106 | 1.1 | 0.32 | 3.4 | 0.5 | 99 | 3.6 | |
| 1.0 | 93 | 3.7 | 1.0 | 94 | 3.7 | ||||||
| Swimming pool water 2 | 23.56 | 1.3 | 0.1 | 107 | 5.6 | 0.35 | 6.4 | 0.1 | 107 | 3.7 | |
| 1.0 | 91 | 5.6 | 10.0 | 108 | 0.5 | ||||||
| Swimming pool water 3 | 22.04 | 0.1 | 0 | – | – | 0.97 | 8.1 | 0 | – | – | |
| Swimming pool water 4 | 18.47 | 1.0 | 0 | – | – | 0.96 | 4.2 | 0 | – | – | |
| Turbidimetry/DPD method | Pure water 1 | < MDL | NA | 0.08 | < MDL | NA | < MDL | NA | 0.08 | < MDL | NA |
| Pure water 2 | < MDL | NA | 0.5 | < MDL | NA | < MDL | NA | 0.5 | 83 | 9.3 | |
| Pure water 3 | < MDL | NA | 1.0 | < MDL | NA | < MDL | NA | 1.0 | 106 | 5.9 | |
| Pure water 4 | < MDL | NA | 0.5 | < MDL | NA | < MDL | NA | 0.5 | 91 | 2.2 | |
| Tap water 1 | < MDL | NA | 0 | – | – | 0.17 | 7.8 | 0 | – | – | |
| Tap water 2 | < MDL | NA | 0 | – | – | 0.14 | 10.6 | 0 | – | – | |
| Rain water 1 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| Rain water 2 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| Lake water1 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| Lake water2 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| River water1 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| River water2 | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| Wastewater effluent | < MDL | NA | 0 | – | – | < MDL | NA | 0 | – | – | |
| Swimming pool water 1 | 13.89 | 8.5 | 0 | – | – | 0.38 | 7.4 | 0 | – | – | |
| Swimming pool water 2 | 23.35 | 3.1 | 0 | – | – | 0.37 | 7.8 | 0 | – | – | |
| Swimming pool water 3 | 22.94 | 2.7 | 0 | – | – | 0.98 | 6.0 | 0 | – | – | |
| Swimming pool water 4 | 18.20 | 3.2 | 0 | – | – | 0.88 | 5.7 | 0 | – | – | |
NA: not applicable; -: test not done.