Study on essential and toxic elements intake from drinking of Chinese tea

Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements, by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined (i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported. Adult daily intakes of some essential and toxic elements from tea drinking were also estimated.     

原子吸收和原子荧光光谱法测定茶园土壤中的微量元素

采用微波消解-火焰原子吸收和原子荧光光谱法同时测定了贵州梵净山茶园土壤中14种微量元素含量,方法简单、准确、迅速,有助于全面、迅速地了解茶园土壤中微量元素的含量,对于特色茶叶品质鉴定和指导合理科学栽培茶树等方面有重要意义.     

茶叶专用营养剂对金萱茶微量元素和黄酮的影响

为探讨茶叶专用植物营养剂对金萱茶微量元素和黄酮含量的影响,以自研制的茶叶专用植物营养剂做试验,分别以稀释300、500、800倍施用到金萱茶中,采取每轮茶施肥一次,并以喷清水、1%尿素和其它品牌的茶叶营养剂稀释300倍作参照,用等离子体原子发射光谱法和分光光度法对施用不同肥料的金萱茶微量元素和黄酮含量分别进行了测定。结果表明,施用自研制的茶叶专用植物营养剂,金萱茶Ca,Mg,Fe,Zn,Mn,Cu,B等微量元素含量大大增加,黄酮含量也显著增多,这与施加含有益活性菌体和多种酶及微量元素的肥料有关。     

Determination of essential and toxic elements in Libyan foodstuff using instrumental neutron activation analysis (INAA)

Since there is no database in Libya defining the intake of the individuals from different essential (minor and trace) and toxic elements provided through food, drinking water and aerosol, a project has been proposed with the cooperation of IAEA to determine the concentration of a number of elements such as Cs, Fe, Cr, Rb, Sc, Se, Co, Zn in the three mentioned sources. Emphasis was placed on the use of nuclear and nuclear-related techniques. In this paper, the primary results are presented for the concentration of minor and trace elements in some vegetables, spices and other foods which are widely used in the Libyan meals. Instrumental neutron activation analysis utilizing a 10 MW water pool reactor and a γ-ray spectroscopy facility was employed. For quality control, certified reference materials were analyzed simultaneosly with the samples which show good agreements compared with the certified data. Emphasis was given to both elements iron and zinc for their importance.     

Determination of trace elements in tea leaves by neutron activation analysis

Instrumental neutron activation analysis has been employed to determine 14 trace elements in two brands of Iranian and foreign tea. The elements are: Br, La, Ba, K, Mn, Cl, Cr, Cs, Rb, Fe, Co, Zn, Sc and Au. The transference ratio of the elements into solution, when tea is leached by percolation, is also reported. It was found that some elements are totally transferred into solution and some are partially retained by the leaves.     

Instrumental neutron activation analysis for multi-elemental determination in Indian tea samples

Instrumental neutron activation analysis (INAA) was employed to determine concentrations of 19 elements (As, Ba, Br, Ce, Co, Cr, Cs, Fe, K, La, Mn, Na, Nd, Rb, Sc, Sm, Th, Yb and Zn) in a large number (55) of tea samples (from market as well as virgin tea leaves) from different locations in India (Assam, Darjeeling, Munnar and Kangra). The results obtained in the present work are compared with those reported in literature. The concentration levels, their variations with collection locations and the correlations among different elements in these samples are discussed.     

湛江市不同茶场出品的绿茶茶水中微量元素的测定分析

采用原子吸收法测定了湛江不同茶场出品的绿茶茶水中的锌、铜、铁、钙、镁、锰、镉、镍、铅的含量。结果显示，绿茶茶水中含有较丰富的多种矿物元素和人体必需的微量元素，不同茶场出品的绿茶茶水中微量元素含量有所不同，浸泡次数不同，微量元素含量不同，第一次浸泡的茶水中微量元素的含量明显大于第二次浸泡。     

原子吸收光谱法测定茶叶中铅和镉时消解方法的优化

采用多种方法对同一种茶叶进行消解,用原子吸收光谱法测定不同方法消解的茶叶中有害微量元素铅和镉的含量并进行对比,探索了茶叶中微量元素铅和镉低损耗的最佳消解条件.实验结果表明,不同的消解方式对茶叶中微量元素的测定结果影响很大.测定茶叶中铅和镉元素时,采用硝酸-高氯酸加盖浸泡过夜方法较为理想.     

Determination of elemental concentrations in environmental plant samples by instrumental neutron activation analysis

The intake of leafy vegetables in daily diet is very important to meet our nutritional needs. Vegetables provide the essential elements which are necessary and recommended for human growth. However, due to rapid industrialization and urbanization our environment becomes polluted and this affects the normal growth of agricultural products and composition of environmental species. The elemental concentrations present in the environmental samples are good indicators to assess the toxicological levels due to pollution affects. In the present work we have analysed several vegetable plant samples by instrumental neutron activation analysis to determine the elemental concentrations at major, minor and trace levels. The leafy vegetables like spinach, red leafy veagetable, pui, gourd leaf, lettuce and katoua were chosen as these are extensively consumed by local peple in eastern part of India. We have determined 15 elements in the above mentioned vegetable samples and some of these are essential elements and some are toxic elements. It was found that Na and K were present as major elements, Fe and Zn as minor elements and As, Ce, Cr, Co, La, Mo, Rb, Sc, Sm, Sr as trace elements. The concentration level of Cr was found to be higher than that of recommended value certified by WHO and National environment quality control for human consumption. The validation of our analytical results have been performed by the Z-score tests through the determination of concentrations of the elements of interest in certified reference materials.     

Determination of trace elements by inductively coupled plasma mass spectrometry of biomass and fuel oil reference materials using milligram sample sizes

Most of the analytical techniques used to quantify elements associated with solid samples suffer from high detection limits and cannot be used for trace elements in biomass samples, particularly when only 20 mg are available for analysis. Inductively coupled plasma mass spectrometry (ICP-MS) can achieve detection limits of parts-per-trillion with liquid sample introduction by solution nebulisation. This technique was therefore tested with two standard biomass reference materials: oriental tobacco leaves and cabbage leaves. Two preparations successfully used on coal standards were used to digest the solid samples: a total digestion method (wet ashing digestion) and a partial leaching (microwave extraction). The concentrations of up to seventeen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn) were measured after the two preparations. The accuracy and sensitivity of the measurements improved when the dilution factor decreased from 5000 to 1000 and to 500. Since the proportion of mineral matter in biomass samples is small (5%), the microwave digestion extracted elements that are generally not completely extracted from coal samples (e.g. Sb). However, some trace element concentrations were below the limit of quantification after microwave extraction, even with a reduced dilution factor (As, Se and Mo) and could not be quantified. A fuel oil was also digested. The trace element concentrations were very low (between 28 and 0.1 microgram g(-1)) but acceptable results were obtained by applying a dilution factor of 100. Only six elements in the fuel oil (As, Ba, Co, Ni, Se and V) had certified or indicated values. Factors affecting the accuracy and sensitivity of the analyses are discussed. The reproducibility of analysis of the tobacco leaf standard was checked over a period of nine months by both digestion methods. The wet ashing method gave acceptable reproducibility for Ba, Cd, Co, Cu, Ga, Mn, Mo, Ni, Pb, V and Zn but poor precision for Cr, Se and Sn and showed evidence of residual chloride interference for As. The microwave extraction gave good reproducibility for As, Ba, Cd, Co, Cr, Cu, Mo, Ni and Zn but poor precision for Se and low recoveries for Ga, Mn, Sn and V. In spite of the small quantities of material analysed, it proved possible to determine the trace elements at levels down to 0.1 microgram g(-1) in the reference materials.     

Multielemental analysis of soil samples by fast-neutron activation

Neutron activation analysis (NAA) have been used for the determination of major, minor, and trace elements in 20 soil samples from 5 crop fields of the Crop Research Centre, Pantnagar, India. Fast neutron activation analysis (FNAA) and cyclic neutron activation analysis (CNAA) have been used to determine the concentrations of various elements. The results for minor and trace elements are compared with the level of abundances of world soils. The present study provides the basic data of elemental concentrations in soil samples of 5 major crop fields located in one of the leading agricultural universities of India for future measurements with the objectives of efficient use of fertilizers and pesticides in accordance with the high yield.     

Chemical characterization of soda-lime glass samples by in situ current normalised PIGE and conventional INAA methods for forensic applications

Nuclear analytical methods namely in situ current normalised Particle Induced Gamma Ray Emission (PIGE) and conventional Instrumental Neutron Activation Analysis (INAA) were utilized for determining major, minor and trace concentrations of eighteen elements in five soda-lime (automobile) glass samples. Concentration of four major elements (Si, Na, Mg and Al) by PIGE and fourteen elements including ten trace elements by INAA were determined. For forensic application, major elements were used for confirming the class of glass samples, whereas concentration results of trace elements like transition and rare earth elements were utilized for finding similarity or differences among the glass samples.

     

Trace elements in human bone determined by neutron activation analysis

There is an evidence that some of the essential trace elements are crucial determinants of bone health. Excess or deficiency of these elements has a role in the development of bone diseases, therefore research on trace elements in bone is very important. Iliac crest bone biopsies were optioned from twelve persons undergoing orthopedic surgery due to any reason than osteoporosis. Cortical and trabecular parts were separated, and blood and fats were removed. Up to 30 minor and trace elements were determined in these samples by instrumental neutron activation analysis and other techniques and their relations were discussed.     

Passive sorption sampling method with neutron activation analysis seems to offer perspective in atomospheric trace-element investigation

Investigations of trace elements in the atmosphere require the application of highly sensitive multielement analytical methods and methods allowing sampling of contrasting element speciations. Instrumental neutron activation analysis was used to determine 30 element concentrations in samples under investigation. The results of investigating properties of aerosol samples on filters and some aspects of the study of atmospheric trace-element vapor-gas and submicron aerosol phases are presented. A method for investigating the vapor-gas and submicron aerosol phases of atmospheric trace elements by sorption on collectors with neutron activation analysis of exposed collectors is offered.     

Multi-element analysis of japanese tea leaves by neutron activation analysis and the single comparator method

The reliability of the single comparator method in neutron activation analysis has been studied by comparing the calculated and experimental k values and by determining the concentration of trace elements in iron. The method has been applied to the analysis of tea leaves for thirteen elements; their concentrations varied over five orders of magnitude.     

Geostandards and geochemical analysis

Progress in geochemical analysis depends on progress in geostandards. The present state of the availability and quality of the geostandards is reviewed for major and trace elements. The several geochemical methods employed are evaluated by their performances in the characterization of geostandards. Signs of progress are visible in the quality of geostandards for major and “common” trace elements. There are also new developments in geoanalytical methods. It is hoped that optical emission inductively coupled plasma spectrometry will play an increasing role in the characterization of trace elements which are normally present in less than 10 ppm concentration levels.Like it or not, progress in geochemical analysis is intimately tied up with the quality of geochemical reference samples (GRS). The converse is true as well; therefore, how well and to what extent international geochemical reference samples are characterized for their chemical composition reflect in a way the current status of geoanalytical methods employed the world over.     

Trace element analysis of airborne particulate matters in relation to air pollution in Benin City, Nigeria

The methods of neutron activation analysis (NAA) and atomic absorption spectrometry (AAS) have been employed to determine the concentration levels of 18 trace elements in filter-collected airborne aerosols over an urban area in Nigeria. The highest concentrations measured in the samples were for Cl, Na, Al, Pb, Ca and Zn. The aerosol particles were found to contain higher concentrations of soil-derived trace elements, such as Al, Ti, K and Na than those derived from combustion and industrial activities such as As, Cd, Mn, Zn, Pb, Ni and Sb. The average precision of measurements varied between +/- 5.2% and 13% for most elements. Possible sources of the elements are also discussed.     

Applicability of ICP-OES,UV-VIS,and FT-IR Methods for the Analysis of Coffee Products

Spectroscopic methods were applied to study and compare the nutrient composition of ground, instant, and chicory coffee products. The total concentrations of 17 elements, including major (Ca, Mg, P) and trace (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sr, Ti, Zn) elements were determined in solid samples and infusions from ground coffee by means of inductively coupled plasma atomic optical spectrometry (ICP-OES). For measurement of As and Se levels, hydride generation technique (HG-ICP-OES) was used. The accuracy of the element measurements was verified by the analysis of certified reference materials (tea leaves (INCT-TL-1), apple leaves (1515), and TORT-2). Caffeine was determined by UV spectrometry. Infrared spectroscopy was applied to investigate organic matter of the coffees. Soluble oxalate was determined by a redox titration. Additionally, measurements of some physico-chemical parameters such as moisture, ash, pH, and starch (coffee adulteration) were performed. Differences in the composition of analyzed ground and instant coffees based on the contents of caffeine, oxalate, and minerals such as Cu, Mg, P, and Zn were found. FT-IR spectroscopy was a suitable tool to characterize the presence of caffeine and oxalate.     

Elemental analysis of the Taiwanese health food Angelica keiskei by INAA

The health food Angelica keiskei, planted and consumed as an oriental herb, was sampled from five farms in Taiwan. The determination of minor and trace elements identified in the roots, fresh leaves and stems of the plant, as well as in end-products such as tea bags and capsules, is essential for estimating the recommended daily intake for ensuring optimum health safety. Samples were homogenized prior to freeze-drying, and were irradiated with a neutron flux at about 2.0^.10¹² n^.cm^-1.s^-1. A total of 17 elements were analyzed using INAA. In the collected samples the elements exist in widely differing concentrations, ranging from 10⁵ to 10^-2 mg/g for different farms. We found that aluminum is more highly concentrated in roots than in any other part of the plant. Selenium was the only element analyzed down to 10^-1 mg/g in the leaves. Meanwhile, arsenic was also found in the roots and stems at levels of nearly 10^-2 mg/g. The elemental concentrations and maximum daily intake (MDI) of this herb are compared with those of Angelica sinensis (Danggui in Mandarin), Ligusticum chuanxiony (Chuanxiong in Mandarin) and Panax ginseng (Ginseng in Mandarin) as well as with the recommended daily dietary intake values for Taiwanese consumers, developed by the WHO.     

Mineral profile of Ghanaian dried tobacco leaves and local snuff: A comparative study

The concentration of thirty-four elements each in Ghanaian dried tobacco leaves and snuff (powdered tobacco) have been determined using instrumental neutron activation analysis (INAA). The concentration of Hg, Cr, As and Cd in both set of samples were found to be in excess of WHO limits for drinking water, thus indicating potential toxicity of the samples. Cr, Cd, Sb and Cu were two to eight times high, whilst As and Hg were comparable in powdered tobacco and tobacco leaves. The aim of the study was to determine the pattern of elemental concentrations and the toxicological strengths in both tobacco leaves and tobacco powder. The results indicated that the toxicity of the snuff was higher than the tobacco. This indicated strongly that from the medical point of view, the level of toxic accumulation in users might be potentially high in the tobacco powder compared to the leaves. Thus, education of the Ghanaian public on the threshold value of toxic elements contained in both set of samples was suggested to safeguard users against these addictives.