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.     

Pollution of agricultural crops with lanthanides,thorium and uranium studied by instrumental and radiochemical neutron activation analysis

The lanthanide elements, Th and U were measured in soils and agricultural crops collected in an area polluted by emissions from a phosphate fertilizer plant. Concentrations of the above elements in the soil and crop samples were determined by instrumental neutron activation analysis (INAA). Selected crop samples were also analyzed using radiochemical neutron activation analysis (RNAA) based on alkaline-oxidative fusion of the irradiated samples followed by precipitation of REE oxalates. Elevated levels of lanthanides, Th and U were found in some samples, especially in wheat chaff and parsley.     

Comparison of major and trace components of Chinese and Canadian soils

INAA was used to determine 32 major and trace elements in 21 soil samples collected from the Loess Plateau, China, and Ontario, Canada. The elemental concentrations determined in different layers of each soil, have been used for comparison in order to find out the general characteristics and any significant differences between Canadian and Chinese soils which developed from similar parent materials. This data can be useful to pedologists and geochemists to study the elemental behaviours and the influences of climate and environment on soil formation. Effort is directed to applying a statistical factor pattern recognition method to these soils for possible use in future soil erosion and transport studies in China. From this study, four soil factors were resolved each for the Chinese and Canadian soils.     

Study of transfer of trace elements from soil to medicinal plants in the environment of Mangalore

The concentration of five trace elements Cr, As, Pb, Rb and Sr in seven medicinal plants Garcinia indica, Ficus benghalensis, Flacartia Montana, Nyctanthes arbor-tristis, Morinda citrifolia, Ficus recemosa, Barringtonia acutangula and associated soils were analyzed using ICP-MS. In plant the elemental concentrations of Cr, Pb, Rb and Sr vary widely and in soil the elemental concentrations of Cr, As and Sr showed wide variation. Selective enrichment of elements Rb and Sr was observed in some plants. The soil to plant transfer ratio was significant for Sr. The results of these systematic investigations are presented and discussed in this paper.     

西南山地煤矿区耕地土壤-农作物重金属富集及健康风险评价

为了解西南某典型山地煤矿区周边农田土壤、农作物重金属的富集情况及对当地人群健康的影响程度,采集矿区周边农田土壤样品和对应的农作物样品,测定重金属Cr、Mn、Zn、As、Pb的含量。运用Nemero指数法、潜在风险指数法对土壤重金属的污染程度进行评价;采用靶标危害系数法(THQ)评价农作物重金属对人体的健康风险。结果显示,Cr、Mn、Zn、As、Pb分别是背景值的1.81、1.90、2.89、1.30、0.86倍,处于轻度污染级别,轻微危害程度。农作物重金属Cr、Pb和As含量的超标情况较严重,Zn的含量超标相对较小。各农作物富集的重金属对人体的健康风险大小为：高粱>玉米>白菜>葱>辣椒。农作物重金属对儿童健康的危害均达到了慢性中毒;对成人健康的影响,高粱处于慢性中毒,其它农作物重金属处于产生较大影响的危害程度。农作物重金属与土壤重金属的相关性分析表明,农作物重金属的含量与土壤重金属全量并无线性关系;各重金属在农作物中的转移能力不同;Pb,As在农作物中的转移能力较大,而Cr相对较小。鉴于矿区重金属的富集情况,应尽快采取修复治理措施,为保证当地人群健康,建议当地居民不再食用和种植富集重金属严重的高粱、玉米农作物。     

Transfer factors of 31 elements in several agricultural plants collected from 150 farm fields in Aomori, Japan

Soil-to-plant transfer factors of 31 stable elements were determined by neutron activation analysis. The transfer factor is one of the important parameters used to estimate the internal radiation dose from radionuclides through food ingestion. In the present study, 12 species of agricultural plants such as root crops, fruit vegetables, green vegetables and pasture grasses, and their soils were collected from 150 farm fields in Aomori prefecture, Japan. The elements described are those that could be detected by this method, which include both essential and nonessential elements for plant growth. The concentrations of individual elements in the cultivated soil samples for each plant were similar in values and their standard deviations were within one order of magnitude, because of the relatively narrow geographic sampling area. The elements were classified into two groups, each having different transfer factor characteristics. In the first group of elements there was an inverse correlation between the transfer factors and the concentrations of elements in the soil, especially for Cl, K and Ca. In the second group, especially Sc and Co, however, the transfer factors were independent of the concentrations of elements in the soil.     

Environmental pollution study by multielemental neutron activation analysis of garden soil samples from Nagpur City, India

A multielemental instrumental neutron activation analysis (INAA) method has been employed for the determination of 30 elements in seven garden soil samples from Nagpur City and two intercomparison soil standards from IAEA, Vienna and Institute of Radioecology and Applied Nuclear Techniques (IRANT), Slovak Republic. Environmental implications of elemental concentrations in different soils have been discussed.     

Geochemistry of Holocene and late Pleistocene soils in the Rouge River and Scarborough Bluffs areas,South-Central Ontario,Canada

Concentrations of major, minor and trace elements were measured in four soil profiles from south-central Ontario. The mean concentration values reported are probably representative of elemental levels in soils formed from sediments reworked by lacustrine and fluvial processes and weathered over the last 12 000 years. The older soils in the sequence (R12, R15 and BRIM1) show declining Na, K, and Al, mainly from Ca dilution, especially in the lower horizons. Iron and Mg levels were not affected by the variations in the Ca concentrations. Arsenic, Br, and Sb concentrations did not increase appreciably in surface A horizons, indicating no measurable airfall influx of industrial pollutants. The relative increase in Mn/Al in the lower horizons of the older soils may be related to leaching by soil or ground water movement.     

Effect of Lead Contamination on Soil Microbial Activity Measured by Microcalorimetry

Microcalorimetry was used to investigate the microbial activity in three types of soil (orchard soil, crop soil, forest soil) in Wuhan, China, and to evaluate the influence of different concentrations of lead (Pb²⁺) on soil microbial activity. The experimental results revealed that due to different physical and chemical characteristics of the soils, soil microbial activity in three soil samples were in a descending sequence: orchards soil, crops soil, forest soil. Six levels of Pb viz. 0, 10, 20, 40, 80, 160 μg·g⁻¹ were applied in these soils, and the results showed that an increase of the amount of Pb²⁺ is associated with a decrease in microbial activity in the soils due to the toxic effect of Pb²⁺. In order to gain further insight of the sequential change of microorganisms, determination of colony forming units (CFU) was performed to provide a negative linear correlation between the heat effect and the respective number of microorganisms in the system.     

A provenance study of coffee by photon activation analysis

Photon activation analysis (PAA) is a multi-elemental radioanalytical technique in trace elements analysis with high accuracy and precision. Researchers at the Idaho accelerator center performed PAA analysis on coffee samples from several locations around the world as an initial step in assessing the relationship between trace elements in illicit drugs and the soils in which they were grown. The preliminary results show coffees from different locations have different concentrations of trace elements. In the three cases where we have soil samples, the matrices of elements in the coffee samples are closely related to the matrices of the elements of the local soil samples. The majority of trace elemental content is similar to that of the local soil sample in which the coffee is planted. It may be that coffee assimilates numerous elements from the soil where it is grown in similar ratios as is found in the soil. Thus, it is conceivable that the elemental content could serve as “fingerprint” to trace the origins of the coffee. To verify our analytical results we applied X-ray fluorescence (XRF) methods as well. Our PAA results are consistent with XRF experimental data. The future of tracing the origin of illicit drugs with the PAA technique is promising.     

Can impurities from soil-contaminated coffees reach the cup?

Depending on the harvest conditions, coffee beans can be contaminated by soil when dropped to the ground. It is well known that agricultural soils act as sinks for agrochemicals applied to the crops. While coffee is brewed, substances present in the roasted and ground coffee beans are extracted by hot water, emphasizing the need to assess the possible transfer of impurities from the soil to the beverage. Soil-contaminated samples of roasted coffee beans were split into 2 groups according to the treatments: (a) washed and ground and (b) only ground. Brewing was performed in a household espresso machine for both coffees. The resulting beverage was freeze-dried and the elemental composition determined by instrumental neutron activation analysis (INAA). The mass fractions of the terrigenous elements Fe, La, Sc, Sm and Th in the freeze-dried non-washed coffee beverages were, at least, 2 times higher than in the washed samples. These elements are tracers of the soil, indicating that the impurities from the soil reached the beverage.     

Radionuclide, Metal and Non-metal Levels in Percolated Water from Soils Fertilized with Phosphogypsum

Phosphogypsum (PG) is a by-product of the phosphate fertilizer industry, which is produced by precipitation during the wet process of phosphate rocks. While commercial uses, in agriculture and in manufacturing gypsum board and Portland cement, consume less than a few percent of this by-product, the vast majority is disposed of on land in gypsum. In Brazil, three main industries are responsible for the production and storage of about 5.5 × 10⁶ tons per year. PG may contain trace metals, non-metals, fluorides and natural radionuclides. Since, in Brazil, PG has been used for many years as soil amendment, it is important to know its availability, mainly in aquatic environments used for human consumption. In this case, more restrictive limits must be adopted. This work aimed to evaluate the mobility of metals in sand and clayey soils and, consequently, the contamination of drainage water through greenhouse-scale leaching and transport of toxic elements and radionuclides from soils fertilized with PG to crops. In general, it was observed that elemental concentrations were below the actual detection limit of the equipment for all conditions of interest, indicating a low mobility of the analyzed elements in the soil.     

Atlantic Forest: A natural reservoir of chemical elements

The accumulation of chemical elements in biological compartments is one of the strategies of tropical species to adapt to a low-nutrient soil. This study focuses on the Atlantic Forest because of its eco-environmental importance as a natural reservoir of chemical elements. About 20 elements were determined by INAA in leaf, soil, litter and epiphyte compartments. There was no seasonality for chemical element concentrations in leaves, which probably indicated the maintainance of chemical elements in this compartment. Considering the estimated quantities, past deforestation events could have released large amounts of chemical elements to the environment.     

Evaluation of soil to tea plant elemental correlation using instrumental neutron activation analysis

Instrumental neutron activation analysis using relative and k ₀-based internal monostandard methods were employed for determination of concentrations of 12 elements in soil and tea plants collected from three different tea producing regions in India namely Assam, Darjeeling and Kangra. A total of 17 tea leaf samples along with corresponding soil samples were analyzed for elemental content. The obtained concentration data was used for the soil–plant elemental correlation studies. Positive correlation was observed between elemental concentrations of tea plants and the associated soil with Pearson correlation coefficient values in the range 0.6–0.9 for ten elements. Variations in transfer factor values were also observed according to the geo-chemical variation.     

Rapid soil analyses of overburden material from historic mines with SNMS

Plasma-based Secondary Neutral Mass Spectrometry (SNMS) is designed and usually used for depth-resolved determination of the elements in inhomogeneous samples. This report shows that it is also advantageous for the quantification of the total elemental inventory of granular material. As an example of such an application, the quantitative elemental analysis of soil samples from residues of three historic mines in Baden-Württemberg is presented. The results obtained with SNMS, using a high primary energy of E_p = 1340 eV, were compared to the concentrations measured by Atomic Absorption Spectroscopy (AAS) and X-Ray Fluorescence (XRF). A reasonable correspondence was found with a mean deviation between all three methods of about 50%. However, SNMS measurements of standard soils, without any matrix adaptation of the elemental sensitivities, exhibited mean deviations from the certified concentrations of only 20–30 wt% down to concentrations below 10^–2 wt%. The advantages of SNMS against AAS and XRF are its simple sample preparation and the rapid detection of all elements in the analyzed material within some 10 min. In each of the three samples chromium, nickel, copper, zink and lead (only sample HS 64) were found in concentrations exceeding the limiting values of the German Sewage Sludge Ordinance (SSO).     

Comparison of bauxites from Jamaica,the Dominican Republic and Suriname

Summary Neutron activation analysis, energy dispersive X-ray fluorescence and natural radioactivity measurements were used to determine 32 elements in three NIST bauxite SRMs from Jamaica, the Dominican Republic and Suriname, and the data related to the concentrations in 25 Jamaican bauxite soil samples. TheSRMs from Jamaica and the Dominican Republic fit theprofile of typical bauxitic soils from Central Jamaica, and the observed similar high values of Cd suggest that these bauxites may have similar origins. Except for Al, the bauxite from Suriname exhibits a very different elemental profile.     

Development of Resin Membranes as a Sensitive Indicator of Heavy Metal Toxicity in the Soil Environment

Abstract

Ion exchange resins in contact with soil can act as a sink for metal cations, thereby simulate the action of plant roots. Ion exchange resins in membrane form offer additional advantages in ease of use and handling. A procedure was developed to assess the bioavailability of four heavy metals Cd, Cr, Ni and Pb via direct in soil burial. A growth chamber experiment with three representative crops (oats, radish and lettuce) was set up to determine the phytotoxic levels of the four heavy metals. The critical levels varied widely from crop to crop, and soil to soil. Lettuce was most sensitive to high concentration of metals. The toxic effects are more pronounced on sandier textured soils.     

Rapid multielemental analysis of Chinese reference soils by laser ablation inductively coupled plasma-source mass spectrometry

Summary Laser ablation inductively coupled plasma-source mass spectrometry has been used to determine thirty elements (Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, As, Rb, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Dy, Ho, Yb, Hf, Ta, W, Th, U) in seven Chinese reference soils. The Surrey prototype spectrometer was employed with sample ablation by a free-running ruby laser. Concentrations in the soils (GSS-2 to GSS-8) were calculated from elemental responses and sensitivities derived from another soil in the series, namely GSS-1. Comparisons with previous neutron activation analyses are made. Rapid semiquantitative analyses are proved feasible. About eighty percent of the LA-ICP-MS determined concentrations were within a factor of two of the concentrations measured by INAA, and many were considerably closer than this. Precisions were typically in the range 2–10% RSD, but some were considerably poorer for elements present at trace levels.     

Cadmium Tolerance and Bioaccumulation of 18 Hemp Accessions

Hemp (Cannabis sativa L.) is a fast-growing and high biomass producing plant species, which has been traditionally grown as multiple-use crop and recently considered as an energy crop. In order to screen accessions that can be cultivated in cadmium (Cd)-contaminated soils for biodiesel production, the ability of Cd tolerance and bioaccumulation of 18 hemp cultivars or ecotypes were evaluated in pot experiment under 25?mg Cd kg(-1) (dry weight, DW) soil condition, in terms of plant growth, pigment contents, chlorophyll fluorescence, and Cd accumulation at 45?days after seedling emergence. Results showed that seedlings of all cultivars, except USO-31, Shenyang and Shengmu, could grow quite well under 25?mg Cd kg(-1) (DW) soil condition. Among them, Yunma 1, Yunma 2, Yunma 3, Yunma 4, Qujing, Longxi, Lu'an, Xingtai, and Shuyang showed great biomass (>0.5?g plant(-1)), high tolerance factors (68.6-92.3%), and little reduction of pigment content and chlorophyll fluorescence under 25?mg Cd kg(-1) (DW) soil stress, indicating these cultivars had a strong tolerance to Cd stress and could be cultivated in Cd-contaminated soils. Cultivars Longxi, Lu'an, Xingtai, Yunma 2, Yunma 3, Yunma 4, and Qujing exhibited higher Cd concentrations and total Cd in shoots. These cultivars, therefore, are good candidates for the implementation of the new strategy of cultivating biodiesel crops for phytoremediation of Cd-contaminated soils.     

A preliminary study of background concentrations of elements in plants of the Xizang Plateau

A total of 29 major and trace elements have been determined in 43 plant samples collected from the Xizang (Tibet) Plateau using INAA at a SLOWPOKE mini-reactor in order to study elemental background concentration values in Xizang plants. In this paper are reported elemental concentrations of different parts of the plants compared to average values of plants worldwide. The preliminary results suggest that nutritional, plant elements in this region are quite low indicative of a state of malnutrition, while the contents of Al, Ti, Cr and Ba are comparatively high. These findings indicate that the concentrations of most elements in the plants are mainly affected by local soil geochemical characteristics. Some variation in elemental distribution within the plants was also evident: in general, higher concentrations were found in stems compared to roots, and, differences for nutritional elements among the plant species were much greater than found for other elements.