| Autor: |
Santos, Sérgio Ricardo Bezerra dos, Araújo, Mário César Ugulino de, Barbosa, Rodrigo Aquino |
| Zdroj: |
Analyst; January 31, 2002, Vol. 127 Issue: 2 p324-327, 4p |
| Abstrakt: |
Alcoholic grade determination in beverages is usually carried out by laborious, slow and expensive processes such as distillation or chromatographic measurements. To overcome these drawbacks, a simple, automated, flow injection system using a photocolorimeter based on a light-emitting diode (LED) as source of radiation and a phototransistor as photodetector is proposed. The alcohol determination is based on refractive index gradient (Schlieren effect) measurements when beverages are injected into an inert carrier stream (water) of a FIA configuration that presents limited mixing conditions. The system was applied to wine, gin, rum, vodka and sugar cane-based beverages known as cachaça available in Brazil. The alcoholic grade determination in these alcoholic beverages showed a relative standard deviation of 3.4% and a mean relative error of 3.0% (n = 10). The developed system processes 120 samples per hour with consumption of 250 μl of sample and no reagent or distillation process is necessary in carrying out the analysis. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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