Metal Species In Samples Research Articles

국내 도료공정 발생 폐기물 중 미규제 중금속류의 배출특성

This study was performed to investigate the contents and leaching characteristics of hazardous wastes from the paint industry. In order to establish a hazardous waste list, samples from industrial discharge have been analyzed for 8 non-regulated inorganic hazardous substances (i.e., Sb, Ni, F, V, Ba, Zn, Be, Se). In more detail, hazardous waste samples from a total of 64 workplaces, e.g. manufacture, formulation, supply and use (MFSU) of coatings, adhesives, sealants and printing inks processing, have been chosen and analyzed. Contents and leaching tests for inorganic metal species in samples show that the non-regulated hazardous substances satisfy all the criteria, while quantitative analyses reveal that some samples of the discharged wastes exceeded the criteria proposed by NIER (National Instituted of Environmental Research). In conclusion, we expect the outcome of this study to align the classification system of hazardous waste management in South Korea with international legislations, and consequently contribute to reduce environmental pollution as well as health risks by toxic wastes.

Ultrasonic extraction as a sample preparation technique for elemental analysis by atomic spectrometry

This work presents performance data after ultrasonic extraction (UE) for the elemental analysis of a number of metal species in samples of interest in environmental and occupational health. In this study, several National Institute of Standards and Technology (NIST) Standard Reference Materials® (SRMs) were subjected to UE in various acid solutions. The extraction solutions employed were 25% nitric acid (v/v), 25% nitric–hydrochloric acids (v/v) and concentrated nitric–hydrochloric acids (1∶1). NIST SRMs 1648, 1579a, 2583, 2704, 2710, 3087a, and 8074 were subjected to these acid conditions and ultrasonic energy (about 1 W cm−2), and elemental recoveries were determined following analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES). Observed recoveries were higher overall with HNO3–HCl mixtures than with nitric acid alone, and recoveries were generally higher for concentrated acid mixtures. Recoveries of >80% could be achieved for some elements (As, Cd, Cu, Mn, Pb, Zn) when using acidic ultrasonic treatment with no deliberately added heating, even under diluted acid conditions. However, several elements (Ba, Co, Cr, Fe, Mg, Ni, V) yielded <75% recoveries when using sonication without deliberate heating, even in concentrated HNO3–HCl. For comparison with UE, selected SRMs were subjected to acid leaching (no sonication) in the above acid solutions. Elemental recoveries from acid leaching without sonication were generally lower overall when compared to results obtained from UE, thereby demonstrating the effect of ultrasound for the dissolution of target analytes. Sonication of chromate-containing certified reference materials and certified filter samples (European Commission Certified Reference Material 545) in slightly basic buffer solutions was shown to be effective for the complete (>90%) dissolution of hexavalent chromium (CrVI) from both soluble (potassium chromate) and insoluble (lead chromate) CrVI reference sources. Sonication in HNO3–HF was used to extract Cd, Fe, Pb and Zn from aerosol filters, water rinsates and aerosol samplers alone; ICP-AES was used for elemental measurement. Sample losses were found for these four elements from rinsates and samples following removal of the aerosol filter, thereby demonstrating the utility of carrying out sonication directly within the aerosol sampler containing the filter. It is hypothesized that UE will be increasingly used for analytical sample preparation purposes.