An assessment of sampling, preservation, and analytical procedures for arsenic speciation in potentially contaminated waters

2007 ◽  
Vol 29 (4) ◽  
pp. 337-346 ◽  
Author(s):  
Youn-Tae Kim ◽  
Hyeon Yoon ◽  
Cheolho Yoon ◽  
Nam-Chil Woo
2020 ◽  
Vol 35 (2) ◽  
pp. 215-237 ◽  
Author(s):  
Francisco Ardini ◽  
Greta Dan ◽  
Marco Grotti

Relevant 2004–2018 papers on arsenic speciation analysis of environmental samples have been reviewed, with the focus on the analytical procedures according to the matrix investigated and the species researched.


Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.


2020 ◽  
Vol 19 (6) ◽  
pp. 1035-1055 ◽  
Author(s):  
S.V. Pankova ◽  
V.V. Popov

Subject. The article considers the development of a set of methods and indicators of economic analysis, which can be used for performance audit of customs authorities, using the Volga Customs Administration case. Objectives. The aim is to justify the use of analytical procedures to rank the effectiveness of customs payments for the purpose of performance audit of customs authorities. Methods. We employ general scientific methods of research, i.e. dialectical and monographic methods, logical analysis, comparison, as well as the Euclidean distance method. Results. We reviewed works by Russian and foreign scholars on the history of customs audit development and internal financial control of customs authorities, gave scientific credence to attributing the system of customs payment and performance to the indicators of economic activity of customs authorities. Due to the lack of methods for assessing the performance of customs authorities, the use of analytical procedures during the performance audit seems to be a promising area. Conclusions. When verifying the scientific hypothesis put forward in the study, we established that the introduction and development of the ranking system for the performance of customs authorities related to the collection of customs duties can contribute to effective financial audit of customs authorities in general.


2020 ◽  
Vol 57 (2) ◽  
pp. 85-93
Author(s):  
B Sinha ◽  
K Bhattacharyya

The purpose of the present study was to assess arsenic (As) speciation in rice from West Bengal, India, in order to improve understanding of the health risk posed by arsenic in Indian rice. Rice is a potentially important route of human exposure to arsenic, especially in populations with rice-based diets. However, arsenic toxicity varies greatly with species. Determination of arsenic (As) species in rice is necessary because inorganic As species are more toxic than organic As. Total arsenic was determined by inductively coupled plasma mass spectrometry; arsenite, arsenate, monomethylarsonic acid, and dimethyarsinic acid were quantified by high-performance liquid chromatography- inductively coupled plasma mass spectrometry. The analysis of a rice flour certified reference material (SRM-1568-a) were evaluated for quality assurance. The use of 2M TFA for extraction with an isocratic mobile phase was optimized for extraction and employed for arsenic speciation in rice. The extraction method showed a high recovery of arsenic. Most of the As species in rice were noticed to be inorganic [Arsenite (As-III), Arsenate As-V]. It appeared very clear from the present study that inorganic arsenic shared maximum arsenic load in rice straw while in grains it is considerably low. As species recovered from rice grain and straw are principally As-III and As-V with a little share of DMA and almost non-detectable MMA and As-B. The order of As species in rice grain revealed in this study were As-III (54.5-65.4 %)>As-V(21.2-28.3%)>DMA(5.2%).


1981 ◽  
Author(s):  
Dwayne D. Neal ◽  
Steven H. Hoke ◽  
William P. Spencer

In the 50 years since magnetoencephalography (MEG) was invented, various clinical and research applications of it have been attempted with considerable success. This is most notable in the area of epilepsy and presurgical functioning mapping. However, the best ways to apply MEG and interpret the findings still remain conjectural. As such, this book assesses the new clinical and research applications of MEG, especially for markers of neuropsychiatric and other disorders. It also evaluates the new instruments and analytical procedures that have been recently developed. Ultimately, the book may serve as a standard of clinical practice and as a source of ideas for expanding the applications of MEG.


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