| 摘要 |
The increased use of reusable bottles is linked with effective purification prior to refilling. Unfortunately, a considerable number of reusable containers are sent back with urine and hydrocarbon contamination (solvents/fuels). Detection of hydrocarbons is done using photoionization detectors or mass spectrometers, which permit a reliable selection. These measuring techniques are not applicable to urine, or only so with serious limitations. The method described here ensures that containers with residual urine can be reliably identified and sorted out. Depending on the age of the urine, ammonia (NH3) is released into the atmosphere, with detected quantities ranging from 3 to about 35 ppm in fresh or 14-day-old reference samples. The method used to measure these is based on the recognition of NH3, with the ammonia being burned catalytically or in a high-temperature converter to produce NO (nitrogen monoxide), which is then reacted with ozone. The energy released in this consequent reaction takes the form of light (chemiluminescence). This light is measured and provides a mesure of the ammonia present. The field of applications is that of monitoring sanitation with respect to reusable bottles and containers in the food and drink industries. |
