ABSTRACT
Objective@#To establish a method for determination of lead and istope ratios in the blood by ISIS-ICP-MS.@*Methods@#After wet digestion, the blood sample was on-line addition of thallium as internal standard and analyzed by ISIS-ICP-MS.@*Results@#The limit of detection was 0.03 μg/L and the lower limit of quantification was 0.08 μg/L. The detection concentration was 0.45 μg/L and the minimum quantitative concentration was 1.49 μg/L. The relative standard deviations (RSD) were 0.3%~1.7%. The recovery was between 91.0% and 103.4%. The precision of the major lead isotope ratios was better than 0.3%. The calibrated isotope ratios of the standard liquid are close to the certificate.@*Conclusion@#The method has a low detection limit, good precision and high accuracy, it is feasible for determination of lead concentration and isotope ratios in the bloune.
ABSTRACT
The seventy samples of Polygoni Multiflori Radix were collected from three producing areas: Bozhou, Anhui province, Jingmen, Hubei province and Xichang, Sichuan province. Three stable isotope ratios and contents of 44 elements in the Polygoni Multiflori Radix samples were determined by EA-IR-MS and HR-ICP-MS. Three data mining methods，including partial least square discriminant analysis (PLS-DA), fisher linear discriminant analysis (FLDA) and decision tree CHAID were employed to establish a model for geographical origin discrimination．The study results showed that the stable isotope ratios expressed significant difference followed with the different producing areas, and will be used to discern the samples from different producing areas, effectively. Combined with the data of elemental analysis, the accuracy rates of model can be further improved. All the three methods showed the accuracy rates of external sample were over 90% using training dataset. These results confirmed that stable isotope ratios and multi-elemental analysis combined with chemometric method was effectiv in geographical tracing of Polygoni Multiflori Radix．The analysis method has great potential and prospect in geographical origin discriminant of Chinese medicinal materials, and provids a new study method to identify origin information of Chinese medicinal materials.
ABSTRACT
The isotopic ratios of strontium isotope (Sr) and light elements (C/H/O/N) in Dendrobium officinale from different producing areas (Shaoguan, Guangdong; Yulin, Guangxi; Shibing, Guizhou; Wenshan, Yunnan and Zhejiang province) were determined with thermal ionization mass spectrometry (TI-MS) and isotope ratio mass spectrometry (IRMS)．The differences of the stable isotope ratios in D. officinale were obtained by the variance analysis and the correlation analysis, and pattern recognition techniques with principal component analysis (PCA) was used to classify the geographical origins of D. officinale from different producing areas．The isotopic ratios of strontium isotope can be used to identified D. officinale in Zhejiang province, and the isotopic ratios of light elements showed the difference followed with the different producing areas. For δD and δ¹⁸ O in samples, maybe influenced by the environment effect. A positive correlation was found between δD and δ ¹⁸O.The principal component analysis was used to discern the samples of D. officinale from different producing areas based on detection technology of stable isotope ratios.These results revealed that it was possible and feasible to classify the geographical origin of D. officinale by the method of determination of isotopes,and provided a new method to identificate origin information of Chinese medicinal materials.
ABSTRACT
In order to define the effect of nutrient enrichment on trophic webs in an Andean mountain stream we performed an experiment using stable isotope ratios (δ15N and δ13C) to analyze different trophic compartments: 1) basal level: CPOM and biofilm; 2) primary consumers - macroinvertebrates: collector-gatherers (Heterelmis sp., Thraulodes sp. and Trichorythodes sp.), and collectorfilterers (Simulium sp.); 3) predators - fish (Oncorhynchus mykiss and Trichomycterus bogotensis). The average fractionation of nitrogen among the primary consumers with respect to CPOM was 4.7 , and 1.7 with respect to biofilm. Predators incremented their δ15N signal by 5.9 % with respect to primary consumers. A depletion of δ15N was observed in Impact with respect to Control reach after fertilization in different compartments (biofilm, Heterelmis, Simulium andTricorythodes), while depletion was not significant for top predators. In most cases, the δ13C signal of biofilm overlapped with that of primary consumers, but a clear enrichment was observed with respect to CPOM. Macroinvertebrate gut contents showed fine detritus to be their most abundant food, and that in general there were no changes in diet as a consequence of nutrient enrichment. The only exception was Heterelmis, who increased its consumption in the Impact reach.
Con el fin de determinar el efecto del incremento de nutrientes sobre la red trófica de un río de montaña andino, se realizó un experimento en donde se analizaron las proporciones de isotopos estables (δ15N y δ13C) para analizar los siguientes compartimientos tróficos: 1) Nivel basal: CPMO y Biofilm; 2) Consumidores primarios - macroinvertebrados: colectores - recolectores (Heterelmis sp., Thraulodes sp., yTrichorythodes sp.) y colectores - filtradores (Simulium sp.); 3) Depredadores - peces (Oncorhynchus mykiss y Trichomycterus bogotensis). La fracción promedio de nitrógeno entre los consumidores primarios con respecto a CPOM fue de 4.7 , y de 1.7 con respecto al biofilm. Los depredadores incrementaron en un 5.9 % la señal δ15N con respecto a los consumidores primarios. Después de la fertilización, se observó en diferentes compartimientos (biofilm, Heterelmis, Simulium yTricorythodes) del tramo impacto un agotamiento de δ15N con respecto al control, mientras que el agotamiento no fue significativo para los depredadores superiores. En la mayoría de los casos la señal δ13C del biofilm se sobrepuso con la de los consumidores primarios pero un claro enriquecimiento fue observado con respecto a CPOM. Los macroinvertebrados referidos fueron seleccionados para analizar su contenido estomacal y los resultados nos mostraron que el detritus fino es el alimento más abundante para los invertebrados, y únicamente, Heterelmis mostró, después de la adición de nutrientes, diferencias significativas en el detritus fino y el material vegetal entre el tramo control y el impactado.
ABSTRACT
Objective To ascertain the uranium concentrations and uranium isotopic ratios in drinking water in Xilingol League,the Inner Mongolia Autonomous Region.Methods Drinking water samples were collected in Xilingol League,the Inner Mongolia Autonomous.Region inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine the concentration of uranium and uranium isotope abundance.Results The uranium concentrations in all samples were in the range of 2.73-18.9μg/L,with an average of 8.20 μg/L.Tbe234U/238U isotope ratio varied from 7.513 × 10-5to 3.003 × 10-4 and235U/238U from 7.196 × 10-3 to 7.391 × 10-3.The relative standard deviation (RSD) was less than 0.5％ for234U/238U and 0.2％ for235 U/238U.Conclusions The uranium concentration in samples collected from Dongwuqi was high than 15 μg/L,whih is the limit given by World Health Organization (WHO).The uranium in drinking water originates from the natural environment.The234U is enriched in drinking water.
ABSTRACT
Objective To ascertain the uranium isotopic ratios in surface water samples around nuclear power plants.Methods Water samples were collected in Jiangsu,Shandong and Zhejiang provinces.An efficient separation procedure for the trace uranium concentrated from surface water by tributyl phosphate (TBP) was used.Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determination of low abundance uranium isotopes.Results The 234 U/238 U isotope ratio varied from 4.575 × 10-5to 7.752 × 10-5 and 235U/238U from 7.273 × 10-3 to 7.639 × 10-3.Conclusions The 234U is enriched in the surface water.