APPLICATION OF A DROPLET-PIXE SYSTEM TO STUDY RADIATION EFFECTS ON ECOSYSTEM FUNCTIONING

Droplet PIXE analysis was applied to the study of radiation effects on soil ecosystem functioning. A paddy soil sample was flooded with well water to prepare soil ecosystem specimens (microcosms), and then the microcosms were chronically exposed to gamma rays at a dose rate of 1 Gy day−1 for 5 days. After the final irradiation, a brownish discoloration was observed in the liquid phases of the irradiated microcosms.To clarify the factors causing the discoloration, minerals in the solutions of the microcosms were analyzed by the droplet PIXE system.Elemental profiles from the XRF spectrum showed marked iron peaks. Exposure of microcosms to gamma rays resulted in a decrease in the iron levels. Since iron is released in the form of Fe(II) from the solid soil to the liquid phase, further determination of the Fe (II) levels was performed. The percentages of Fe (II) to the total iron in the liquid phase of the irradiated microcosms were lower than those of the controls. This result may be caused by the change of Fe species from soluble Fe (II) to insoluble Fe (III) during gamma irradiation, and the Fe (III) species with a brownish color may be associated with the discoloration of the irradiated samples. The conversion from soluble to insoluble forms may also contribute the small amount of dissolved iron in the irradiated microcosms. Iron is an essential trace nutrient for plants, and thus the amount of dissolved iron is one aspect of ecosystem functioning. Effects of gamma radiation on the dissolved iron could involve a change in the soil ecosystem through the depression of iron flux in the long term.

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Determination of perfluorinated compounds (PFCs) in solid and liquid phase river water samples in Chao Phraya River, Thailand

Water Science & Technology ◽

10.2166/wst.2011.686 ◽

2011 ◽

Vol 64 (3) ◽

pp. 684-692 ◽

Cited By ~ 5

Author(s):

Chinagarn Kunacheva ◽

Shuhei Tanaka ◽

Shigeo Fujii ◽

Suwanna Kitpati Boontanon ◽

Chanatip Musirat ◽

...

Keyword(s):

Liquid Phase ◽

Suspended Solids ◽

Solid Phase ◽

Industrial Applications ◽

Perfluorinated Compounds ◽

River Water Samples ◽

Liquid Phases ◽

Chao Phraya River ◽

Solid Liquid

Perfluorinated compounds (PFCs), especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are fully fluorinated organic compounds, which have been used in many industrial applications. These chemicals have contaminated surface water all over the world even in developing countries like Thailand. The previous study showed the contamination in Chao Phraya River in 2006 and 2007. The purposes of this field study were to determine the solid and liquid phase of PFCs contamination in Chao Phraya River and to compare the changes of PFC concentration in 2008. Surveys were conducted in the lower reach of Chao Phraya River in the industrialized area. A solid phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis for ten PFCs. Ten PFCs were analyzed to identify the contamination in both solid and liquid phases. PFCs were detected in both the solid and liquid phase in every sample. PFOA was the most dominant PFC while PFPA and PFOS were also highly detected in most samples. The average loadings of PFPA, PFOA and PFOS in Chao Phraya River were 94.3, 284.6 and 93.4 g/d, respectively. PFOS concentrations did not show differences between 2006 and 2008. However, PFOA concentrations were higher in 2008/5/26, while comparing other samplings. The ratio of solid : liquid PFPA (2.1 : 1.0) [(ng/g)/(ng/L)] was lower than PFOA (13.9 : 1.0) [(ng/g)/(ng/L)] and PFOS (17.6 : 1.0) [(ng/g)/(ng/L)]. The shorter chain (more hydrophilic) PFC was better to dissolve in water rather than adsorb onto suspended solids. PFOS also showed more potential to attach in the suspended solids than PFOA.

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Diffusion parameters in liquid phase sintering of the al-cu system

Science of Sintering ◽

10.2298/sos0203203l ◽

2002 ◽

Vol 34 (3) ◽

pp. 203-213 ◽

Cited By ~ 2

Author(s):

O.V. Lapshin ◽

A.P. Savitskii ◽

V.E. Ovcharenko

Keyword(s):

Liquid Phase ◽

Quantitative Determination ◽

Liquid Phase Sintering ◽

Volume Changes ◽

Liquid Phases ◽

Diffusion Parameters ◽

Direct Problems

Within the framework of the conception of the priority of the diffusion of atoms from the liquid phase into the solid at their interface, a method of quantitative determination of diffusion parameters of interaction of solid and liquid phases by experimental curves of growth and densification of powder bodies during liquid phase sintering has been suggested. Results of the determination of diffusion parameters and volume changes of powder bodies of the Al-Cu system during sintering were produced on the basis of solution of the reverse and direct problems.

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Determination of Pyrethroids in Soil by Hollow Fiber-based Liquid Phase Microextraction and Chromatography-Mass Spectrometry

CHINESE JOURNAL OF ANALYTICAL CHEMISTRY (CHINESE VERSION) ◽

10.3724/sp.j.1096.2011.01753 ◽

2012 ◽

Vol 39 (11) ◽

pp. 1753-1757

Author(s):

Yan SHAO ◽

Li-Jun ZHANG ◽

Zhan-En ZHANG

Keyword(s):

Mass Spectrometry ◽

Liquid Phase ◽

Hollow Fiber ◽

Liquid Phase Microextraction ◽

Chromatography Mass Spectrometry

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VARIABLES AFFECTING THE COUNTING OF C*SUP 14/ IN THE LIQUID PHASE WITH A GEIGER-MUELLER TUBE. PART 1. DETERMINATION OF VAPOR-LIQUID EQUILIBRIA OF A TERNARY MIXTURE WITH A RADIOACTIVE TRACER. PART 2 (thesis)

10.2172/4406604 ◽

1953 ◽

Author(s):

T.T. Szabo

Keyword(s):

Liquid Phase ◽

Ternary Mixture ◽

Radioactive Tracer ◽

Vapor Liquid Equilibria ◽

Vapor Liquid

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Multi-walled Carbon Nanotubes Reinforced into Hollow Fiber by Chitosan Sol-gel for Solid/Liquid Phase Microextraction of NSAIDs from Urine Prior to HPLC-DAD Analysis

Current Pharmaceutical Biotechnology ◽

10.2174/1389201020666190405181234 ◽

2019 ◽

Vol 20 (5) ◽

pp. 390-400 ◽

Cited By ~ 1

Author(s):

Nabil N. AL-Hashimi ◽

Amjad H. El-Sheikh ◽

Rania F. Qawariq ◽

Majed H. Shtaiwi ◽

Rowan AlEjielat

Keyword(s):

Carbon Nanotubes ◽

Liquid Phase ◽

Hollow Fiber ◽

Sol Gel ◽

Liquid Phase Microextraction ◽

Extraction Device ◽

Multi Walled Carbon Nanotubes ◽

Solid Liquid ◽

Walled Carbon Nanotubes

Background: The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies. Methods: In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution. Results: The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods. Conclusion: The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.

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