Trace Elements In Environmental Materials Research Articles

Assessing the risks of trace elements in environmental materials under selected greenhouse vegetable production systems of China

The risk assessment of trace elements of different environmental media in conventional and organic greenhouse vegetable production systems (CGVPS and OGVPS) can reveal the influence of different farming philosophy on the trace element accumulations and their effects on human health. These provide important basic data for the environmental protection and human health. This paper presents trace element accumulation characteristics of different land uses; reveals the difference of soil trace element accumulation both with and without consideration of background levels; compares the trace element uptake by main vegetables; and assesses the trace element risks of soils, vegetables, waters and agricultural inputs, using two selected greenhouse vegetable systems in Nanjing, China as examples. Results showed that greenhouse vegetable fields contained significant accumulations of Zn in CGVPS relative to rice–wheat rotation fields, open vegetable fields, and geochemical background levels, and this was the case for organic matter in OGVPS. The comparative analysis of the soil medium in two systems with consideration of geochemical background levels and evaluation of the geo-accumulation pollution index achieved a more reasonable comparison and accurate assessment relative to the direct comparison analysis and the evaluation of the Nemerow pollution index, respectively. According to the Chinese food safety standards and the value of the target hazard quotient or hazard index, trace element contents of vegetables were safe for local residents in both systems. However, the spatial distribution of the estimated hazard index for producers still presented certain specific hotspots which may cause potential risk for human health in CGVPS. The water was mainly influenced by nitrogen, especially for CGVPS, while the potential risk of Cd and Cu pollution came from sediments in OGVPS. The main inputs for trace elements were fertilizers which were relatively safe based on relevant standards; but excess application caused trace element accumulations in the environmental media.

Possibilities of High Resolution Inductively Coupled Plasma Optical Emission Spectrometry in the Determination of Trace Elements in Environmental Materials

This paper presents new quantitative data for the spectral interferences obtained by high resolution 40.68 MHz radial viewing inductively coupled plasma optical emission spectrometry (HR-ICP-OES) in the determination of Zn, Cd, Sb, Cu, Mn, Pb, Sn, Cr, U, and Ba in environmental materials in the presence of a complex matrix, containing Al, Ca, Fe, Mg, and Ti. The �� -concept for quantification of spectral interferences was used. The optimum line selection for trace analysis of a variety of multicomponent matrices requires the choice of prominent lines, which are free or negligibly influenced by line interference problems. The versatility of �� -concept as basic methodology was experimentally demonstrated in the determination of trace of elements in soil and drinking water. The detection limits are lower in comparison with corresponding threshold concentration levels for soil and drinking water in accordance with environmental regulations. This paper shows the possibilities of present day ICP-OES equipment in the direct determination of trace elements (without preconcentration of impurities) in environmental samples.

Determination of barium, chromium, cadmium, manganese, lead and zinc in atmospheric particulate matter by inductively coupled plasma atomic emission spectrometry (ICP-AES)

The present paper has shown that the Q concept, as proposed by P.W.J.M. Boumans, J.J.A.M. Vrakking, Spectrochim. Acta Part B 43 (1988) 69, can be used as a basic methodology in the determination of Ba, Cr, Cd, Mn, Pb and Zn in pairs of atmospheric particles by inductively coupled plasma atomic emission spectrometry (ICP-AES). The data base of Q values for line interference [ Q Ij (λ a )] and Q values for wing background interference [ Q WJ (Δλ a )] were obtained in our former work [N. Daskalova, Iv. Boevski, Spectral interferences in the determination of trace elements in environmental materials by inductively coupled plasma atomic emission spectrometry, Spectrochim. Acta Part B 54 (1999) 1099–1122]. The samples of atmospheric particles were collected by the Bergerhoff method. The ICP-AES determination was performed after sample digestion with aqua regia. Q values were used for the calculation of both the total interfering signal under the analysis lines and the true detection limits, depending on the matrix constituents in the different samples. Comparative data for the concentration of analytes were obtained by flame atomic absorption spectrometry (FAAS) and direct current arc atomic emission spectrographic method (dc arc-AES).

Spectral interferences in the determination of trace elements in environmental materials by inductively coupled plasma atomic emission spectrometry

This paper deals with spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES) encountered with environmental materials. These samples normally contain high concentrations of aluminium, calcium, magnesium, iron, titanium, potassium and sodium. The investigations cover: (a) spectral data for Al, Ca, Mg, Fe, Ti, K and Na as interferents for 200 pm wide windows centred (±100 pm) around the prominent lines of As, B, Ba, Be, Cd, Cr, Cu, Hg, Mn, P, Pb, Sb, Se, Sn, Tl, U and Zn; (b) a data base of Q-values for line interference [ Q I j (λ a)] and Q-values for wing background interference [ Q W j (Δλ a)] for two values of the excitation temperature 6200 K and 7200 K. The lines free or negligibly influenced by line interference were selected for analyte determination. Q-values were used for calculation of correction factors under a spectral line without the measurement of a reference blank at the wavelength of the prominent analysis lines. The accuracy of ICP-AES with the Q-concept as a basic methodology is checked by the analysis of a certified reference material IAEA/Sediment SD-N-1/2/. The precision of the method is characterised by an RSD of 0.6–1.7%. Extraction of trace elements soluble in aqua regia was used as a decomposition method. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta, Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains the tabular material of this article in electronic form.

The problem of accuracy in environmental analysis

Recent interlaboratory trials regarding the determination of trace elements in environmental materials, such as plants, have shown, that despite of acceptable precision most of the participating laboratories were not in the position to produce accurate results for trace elements such as for example lead and mercury.