| Autor: |
Martelli Patrícia B., Rocha Fábio R. P., Gorga Rejane C. P., Reis Boaventura F. |
| Jazyk: |
angličtina |
| Rok vydání: |
2002 |
| Předmět: |
|
| Zdroj: |
Journal of the Brazilian Chemical Society, Vol 13, Iss 5, Pp 642-646 (2002) |
| Druh dokumentu: |
article |
| ISSN: |
0103-5053 |
| Popis: |
A flow system for spectrophotometric multidetermination in waters is proposed. Reagent aliquots (25-75 muL) were inserted into the sample stream, allowing up to 4.5-fold increase in sensitivity and an average 12-fold reduction in reagent consumption. The system allows the determination of phosphate (0.25 fraction three-quarters 5.0 mg L-1), phenols (0.10 fraction three-quarters 1.0 mg L-1), nitrite (0.050 fraction three-quarters 0.50 mg L-1), sulphide (0.10 fraction three-quarters 1.0 mg L-1) and total iron (1.0 fraction three-quarters 5.0 mg L-1) without changing the flow manifold. Detection limits of 150 mug L-1 PO4(3-), 10 mug L-1 phenol, 2 mug L-1 NO2-, 20 mug L-1 sulphide and 15 mug L-1 Fe3+ were estimated at the 99.7 % confidence level. Coefficients of variation were lower than 4 % (n = 20). Results for river and lake water samples were in agreement with the obtained with flow systems with continuous reagent addition at the 95 % confidence level. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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