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Extração de mercúrio de solos e sedimentos auxiliada por ultra-som
| Content Provider | Semantic Scholar |
|---|---|
| Author | Collasiol, André |
| Copyright Year | 2004 |
| Abstract | This work describes a sample preparation method for Hg determination in soil, river sediment and marine sediment. Hg is quantitatively extracted from the investigated marine sediments into 30% (v/v) HNO3 by applying ultrasound radiation (120 s, 70 W) when particles size are ≤ 120 μm. Similar conditions also succeed for river sediment and soil, excepting the time of sonication (180 s) and the need of adding 0.15% KCl. The attained slurries are sonicated, centrifuged, and the Hg is determined in the supernatant by FI-CV AAS. The proposed method was validated by analyzing the CRMs PACS-2 and MESS-3, both from NRCC, Buffalo River (NIST 8704), Montana Soil (NIST 2710), and RS-3 (robin test). The measured concentrations are in agreement with the certified ones. The figures of merit are: characteristic mass of 25 pg, LOD (3s) of 0.2 μg l Hg and LOQ (10s) of 0.012 μg g Hg. These are based on 800 μl of sample solution and 1 g of sample mass in 20 ml of slurry. The proposed method was applied for real samples (soil, river sediment and marine sediment) analysis. The same samples were also analyzed using a digestion method (heating at 85 °C during 3 h) by employing an oxidant mixture (1 to 2% K2S2O8 (m/v) and 30% (v/v) HNO3). The attained results were in agreement. Conventional calibration was used all times, applying matrix matching when KCl or K2S2O8 was used. In order to investigate organic Hg extraction using ultrasound, MeHg was added to the CRM samples. Only circa 5% of the spiked MeHg was transformed into Hg when the proposed method was used, meanwhile, the recovery was circa 100% when the digestion method was applied. Due to this fact a semi quantitative Hg chemical speciation is suggested by using both sample preparation methods. In this case, the total Hg concentration could be determined by using the digestion method, the inorganic Hg could be determined using ultrasound, while the organic Hg could be determined by difference. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://lume.ufrgs.br/bitstream/handle/10183/6136/000437164.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
