Miniaturized and direct spectrophotometric multi-sample analysis of trace metals in natural waters
| Autor: | José A. López-López, Gemma Albendín, Juan J. Pinto |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Biophysics
Analytical chemistry Fresh Water Ammonium fluoride 02 engineering and technology 01 natural sciences Biochemistry Matrix (chemical analysis) chemistry.chemical_compound Spectrophotometry Sodium citrate medicine Molecular Biology medicine.diagnostic_test Chemistry 010401 analytical chemistry Hydrazones Vanadium Cell Biology 021001 nanoscience & nanotechnology Box–Behnken design 0104 chemical sciences Certified reference materials Indicators and Reagents Spectrophotometry Ultraviolet 0210 nano-technology Sodium acetate Copper Masking agent Environmental Monitoring Nuclear chemistry |
| Zdroj: | Analytical Biochemistry. 497:18-23 |
| ISSN: | 0003-2697 |
| DOI: | 10.1016/j.ab.2015.11.025 |
| Popis: | Trends in the analysis of trace metals in natural waters are mainly based on the development of sample treatment methods to isolate and pre-concentrate the metal from the matrix in a simpler extract for further instrumental analysis. However, direct analysis is often possible using more accessible techniques such as spectrophotometry. In this case a proper ligand is required to form a complex that absorbs radiation in the ultraviolet–visible (UV–Vis) spectrum. In this sense, the hydrazone derivative, di-2-pyridylketone benzoylhydrazone (dPKBH), forms complexes with copper (Cu) and vanadium (V) that absorb light at 370 and 395 nm, respectively. Although spectrophotometric methods are considered as time- and reagent-consuming, this work focused on its miniaturization by reducing the volume of sample as well as time and cost of analysis. In both methods, a micro-amount of sample is placed into a microplate reader with a capacity for 96 samples, which can be analyzed in times ranging from 5 to 10 min. The proposed methods have been optimized using a Box–Behnken design of experiments. For Cu determination, concentration of phosphate buffer solution at pH 8.33, masking agents (ammonium fluoride and sodium citrate), and dPKBH were optimized. For V analysis, sample (pH 4.5) was obtained using acetic acid/sodium acetate buffer, and masking agents were ammonium fluoride and 1,2-cyclohexanediaminetetraacetic acid. Under optimal conditions, both methods were applied to the analysis of certified reference materials TMDA-62 (lake water), LGC-6016 (estuarine water), and LGC-6019 (river water). In all cases, results proved the accuracy of the method. |
| Databáze: | OpenAIRE |
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