J. J. van der Lee

Wageningen University, Wageningen, Gelderland, Netherlands

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Publications (6)4.5 Total impact

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    ABSTRACT: For an evaluation of soil fertility status, a multiplicity of soil-analytical methods is in use in many countries. Very often a separate extractant is used for almost every single nutrient. For evaluation of the heavy metal burden of soils, however, in most countries only the ‘total’ concentration is measured after aqua regia treatment. To date, there is no generally accepted method of estimating the bioavailability of heavy metals. A single extraction of soils with 0.01 M CaCl2 is proposed. This extraction is simple, cheap and environmentally friendly. Moreover, the extracting solution matches the soil solution with respect to pH, concentration and composition. Results using this extractant are compared with results obtained by some conventional extraction procedures in use in The Netherlands. For some nutrients and heavy metals analytical results are judged against crop response. Heavy metal concentrations in soils determined by this extraction procedure give a better indication of bioavailability than do total soil contents. Understanding of plant requirement for nitrogen and of heavy metal behaviour in the soil-plant system with the CaCl2 extractant compares favourably with that obtained using other extractants. Using modern methods analyte concentrations in extracts are easily measured.
    Science of The Total Environment. 01/1996;
  • V. J. G. Houba, I. Novozamsky, J. J. van der Lee
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    ABSTRACT: Accreditation of analytical chemical laboratories is becoming a must in today's world. In the case of laboratories dealing with soil and plant analysis, it is not sufficient to tally with rules for accreditation only. Across‐border standardization and validation of analytical procedures as well as participation in international interlaboratory analytical studies, are also highly important if reproducible, comparable and mutually recognized results are to be reached. The way of working of some national and international organizations in the field of accreditation, standardization and validation is described. Furthermore a few interlaboratory analytical studies are discussed in some detail to give examples of this type of work.
    Communications in Soil Science and Plant Analysis 04/1994; 25(7-8):827-841. · 0.42 Impact Factor
  • V. J. G. Houba, I. Novozamsky, J. J. van der Lee
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    ABSTRACT: The increasing demand for analytical data from laboratories in the field of soil and plant analysis and the increasing possibilities of modern instrumentation (speed and multi‐element determinations) ask for a reconsideration of the conventionally used analytical methods together with stronger requirements for quality control.
    Communications in Soil Science and Plant Analysis 04/1994; 25(7-8):753-765. · 0.42 Impact Factor
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    ABSTRACT: For the determination of total element contents in plant material by atomic spectrometry after wet digestion, both dissolution and oxidation of the matrix are necessary. This was achieved by a sequential digestion procedure using first hydrogen fluoride (HF) for dissolution of silicate, followed by oxidation with nitric acid (HNO3) and hydrogen peroxide (H2O2). The final solution is 0.2M HNO3, and contains only traces of HF. Application of the method for the determination of aluminium (Al), boron (B), calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), lead (Pb), sulfur (S), and zinc (Zn) in various materials showed good agreement with certified reference materials.
    Communications in Soil Science and Plant Analysis - COMMUN SOIL SCI PLANT ANAL. 01/1993; 24:2595-2605.
  • V. J. G. Houba, I. Novozamsky, J. J. van der Lee
    Communications in Soil Science and Plant Analysis 11/1992; 23(17-20):2029-2051. · 0.42 Impact Factor
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    ABSTRACT: The extractive powers of different extraction procedures (Electro-Ultrafiltration, 0.01M CaCl2 and standard Dutch methods) were compared mutually for a limited number of nutrients in soil samples from 21 locations. The results showed that for almost all parameters under study (Na, K, Mg, Mn, P, N) the methods are interchangeable. Drawbacks of the EUF technique are lower reproducibility of the results, laboriousness and high cost. Moreover, the extraction of exchangeable forms of Mn and Mg with this technique was incomplete. Extraction with 0.01M CaCl2 seems recommendable due to the simplicity of the analytical procedure giving sufficient information for practical soil-analytical purposes.
    Plant and Soil 09/1986; 96(3):433-437. · 3.24 Impact Factor