Characterisation and analysis of persistent organic pollutants and major, minor and trace elements in Calabash chalk

• Published in: Chemosphere (Oxford) Vol. 57; no. 1; pp. 21 - 25
• Main Authors: Dean, J.R, Deary, M.E, Gbefa, B.K, Scott, W.C
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2004; Elsevier
• Subjects: Air. Soil. Water. Waste. Feeding; aluminum silicate hydroxide; Aluminum Silicates - chemistry; Applied sciences; Biological and medical sciences; Calabash chalk; chalk; Chemical and industrial products toxicology. Toxic occupational diseases; chemical composition; Chromatography, Gas; Chromatography, Supercritical Fluid; Earth sciences; Earth, ocean, space; edible chalk; elements; Energy dispersive X-ray fluorescence spectroscopy (EDXRF); Environment. Living conditions; Exact sciences and technology; food contamination; Gas chromatography with mass selective detection (GC-MSD); Geophagia; Hydrocarbons, Chlorinated; insecticide residues; Insecticides - analysis; kaolin; Lead - analysis; Medical sciences; Metallic and non-metallic deposits; Metals; Metals and various inorganic compounds; organochlorine insecticides; Persistent organic pollutants; pollutants; Pollution; Pollution sources. Measurement results; Public health. Hygiene; Public health. Hygiene-occupational medicine; silicates; Soil and sediments pollution; Soil Pollutants - analysis; Spectrometry, X-Ray Emission; Toxicology; Trace Elements - analysis; traditional foods; Useful material except metal geology; X-Ray Diffraction; Nigeria; Gas chromatography with mass selective detection (GC-MSD); Energy dispersive X-ray fluorescence spectroscopy (EDXRF); Persistent organic pollutants; Geophagia; Calabash chalk; Metals; Elementary analysis; Human; Chemical analysis; X ray fluorescence; Crystal chemistry; Pesticides; Soil pollution; X ray diffraction; Persistent organic pollutant; Gas chromatography; Trace element; Soils; Energy dispersion
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2004.05.023

Analysis of Calabash chalk has been done using energy dispersive X-ray fluorescence spectroscopy (EDXRF), X-ray diffraction (XRD) and pressurised fluid extraction (PFE) followed by gas chromatography (GC) with mass selective detection (MSD). It was found by XRD that the composition of Calabash chalk was an aluminium silicate hydroxide from the kaolin clay group with the possible formula Al
2Si
2O
5(OH)
4. Multi-elemental analysis by EDXRF was able to quantify 22 elements in Calabash chalk including lead at a mean concentration of approximately 40 mg/kg. A range of persistent organic pollutants were identified and quantified in Calabash chalk including alpha lindane, endrin, endosulphan II and
p,
p
′-DDD using PFE-GC-MSD.