• Title/Summary/Keyword: hydride generation method

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Studies on Determination of trace amount of Se in Volcanic Rocks by Atomic Absorption Spectrophotometry (원자 흡수 분광광도법에 의한 화산암중 극미량의 Se정량에 관한 연구)

  • Kim, Chan-Kook;Sung, Hak-Je;Chung, Kang-Sup;Yamaya, Kazuhisa
    • Analytical Science and Technology
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    • v.12 no.6
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    • pp.484-489
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    • 1999
  • The extraction of trace amounts of Se in volcanic rock was investigated using the hydride generation method and atomic absorption spectrophotometry. The powdered rock, 1.0 g, was decomposed with the mixture of $HClO_4$, $HNO_3$ and HF in an acid digestion bomb at $140^{\circ}C$ for 2 hours. For the reduction of Se(VI) to Se(IV) in the solution, 10 mL of 6 M HCl and 0.2 mL of 1 M KBr were added to the solution and the mixture was heated for 30~45 minutes. $H_2Se$ was produced by adding 3% $NaBH_4$ as a strong reducing agent, extracted by nitrogen gas, and was absorbed twice into $KMnO_4$solution. The contents of Se in the solution were determined by generation/AAS. According to the proposed method, 1.0 ng or more of Se was quantitatively extracted and Se levels of 2.5 ng/g or more in rock samples could be determined. For example, Se in a rhyolite was determined with the precision of $19.5{\pm}1.3ng/g$(95% confidence, n=6).

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Comparative Study on Effects of WPH and WPHCR on the anticonvulsive action and Accumulation of Hg & AS in Organ of ICR Mice (우황포용환(牛黃抱龍丸)과 우황포용환(牛黃抱龍丸) 거(去) 주사석웅황(朱砂石雄黃)의 항경련작용(抗痙攣作用) 및 Hg, As의 간(肝).신장(腎臟)에의 축적(蓄積)에 대(對)한 비교연구(比較硏究))

  • Kim Yun-Hee;Lee Han-Cheul
    • The Journal of Pediatrics of Korean Medicine
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    • v.8 no.1
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    • pp.59-74
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    • 1994
  • The Study was performed on the anticonvulsive effects of Woohwangporyonghwan(WPH) and Woohwangporyonghwan except CINNABARIS and REALGAR(WPHCR) in ICR mice pretreated with strychnine, picrotoxin, and caffeine as convulsive agents, and also was done on the accumulation of Hg & AS in organs of ICR mice by ICP hydride generation method. The results were obtained as follows: 1. WPH and WPHCR group showed significant effect in delaying the onset of convulsion induced by strichine, but time to death was effective only in WPHCR group. 2. WPH and WPHCR group were significantly effective in delaying convulsion induced by picrotoxin, and time to death. 3. The anticonvulsive effect of WPH and WPHCR group was not found convulsion induced by caffeine. 4. The accumulation of Hg, AS in liver and kidney of ICR mice was not determined below 50ng/g and below 80ng/g respectively. From the above results it could be concluded that WPH and WPHCR group were effective in the convulsions induced by strychnine and picrotoxin, although the accumulation of Hg & As in liver and kidney was not proved, further study might be necessary to prove the drug safety of WPH included CINNABARIS and REALGAR.

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Determination of Bi Impurity in Lead Stock Standard Solutions by Hydride-generation Inductively Coupled Plasma Mass Spectrometry

  • Park, Chang J.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.233-236
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    • 2004
  • Total impurity analysis of a primary standard solution is one of the essential procedures to determine an accurate concentration of the standard solution by the gravimetry. Bi impurity is determined in Pb standard solutions by inductively coupled plasma mass spectrometry (ICP-MS). The direct nebulization of the Pb standard solution produces a significant amount of the Pb matrix-induced molecular ions which give rise to a serious spectral interference to the Bi determination. In order to avoid the spectral interference from the interferent $^{208}PbH^+$, the hydride generation method is employed for the matrix separation. The Bi hydride vapor is generated by reaction of the sample solution with 1% sodium borohydride solution. The vapor is then directed by argon carrier gas into the ICP after separation from the mixture solution in a liquid-gas separator made of a polytetrafluoroethylene membrane tube. The presence of 1000 ${\mu}$g/mL Pb matrix caused reduction of the bismuthine generation efficiency by about 40%. The standard addition method is used to overcome the chemical interference from the Pb matrix. Optimum conditions are investigated for the hydride-generation ICPMS. The detection limit of this method is 0.5 pg/mL for the sample solutions containing 1000 ${\mu}$g/mL Pb matrix.

Urinary Arsenic Concentrations and their Associated Factors in Korean Adults

  • Bae, Hye-Sun;Ryu, Doug-Young;Choi, Byung-Sun;Park, Jung-Duck
    • Toxicological Research
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    • v.29 no.2
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    • pp.137-142
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    • 2013
  • Arsenic (As) is a well-known human carcinogen and its dietary exposure has been found to be the major route of entry into general population. This study was performed to assess the body levels of As and their associated factors in Korean adults by analyzing total As in urine. Urine and blood samples were collected from 580 adults aged 20 years and older, who had not been exposed to As occupationally. Demographic information was collected with the help of a standard questionnaire, including age, smoking, alcohol intake, job profiles, and diet consumed in the last 24 hrs of the study. Total As, sum of As(III), As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), in urine was determined using atomic absorption spectrometer involving hydride generation method. The geometric mean concentration of total As in urine was $7.10{\mu}g/L$. Urine As was significantly higher in men ($7.63{\mu}g/L$) than in women ($6.75{\mu}g/L$). Age, smoking, alcohol consumption, and job profiles of study subjects did not significantly affect the concentration of As in urine. No significant relationship was observed between body mass index (BMI), Fe, and total cholesterol in serum and urinary As. Urine As level was positively correlated with seaweeds, fishes & shellfishes, and grain intake. A negative correlation between urinary As level and HDL-cholesterol in serum and meat intake was observed. Overall, these results suggest that urinary As concentration could be affected by seafood consumption. Therefore, people who frequently consume seafood and grain need to be monitored for chronic dietary As exposure.