Improvements in calibration procedures for the quantitative determination of trace elements in carbonate material (mussel shells) by laser ablation ICP-MS.
A better repeatability and accuracy in the quantitative determination of trace elements in mussel shells or carbonate-based materials by LA-ICP-MS was achieved by using a series of multielement calibration standards prepared by co-precipitation of twelve elements into a CaCO3 matrix in order to improve the homogeneity of the resulting powder samples. Pressed powder discs of good mechanical stability could be obtained at a pressure of 50 MPa, without the addition of a binder. An UV laser (modified Nd:YAG, 266 nm) was used in the Q-switched mode at a repetition rate of 10 Hz and an energy level of 3.5 mJ. Correlation coefficients (R) for the linear calibration graphs (concentration range: 1.5-400 microg/g) for Cr, Mn, Co, Cu, Zn, As, Cd, Sn, Ba, and Pb are generally better than 0.997. The detection limits for all elements investigated are in the sub-microg/g range. Incorporation of elements into the matrix by co-precipitation has shown as a superior method for producing calibration standards than the simple mixture of the analytes (in carbonate or oxide form) with the matrix (CaCO3) or addition of standard solutions to a carbonate powder base. Two examples of the quantitative determination of toxic elements in mussel shells will be presented.
Bellotto
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VR
CTTMar-Center for Technology, Earth and Ocean Sciences, Vale do Itajaí University, Santa Catarina, Brazile. bellotto@cittmar.univali.rct-sc.br
Miekeley
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N
D000818:Animals; D049872:Bivalvia; D002138:Calibration / Q000592:standards*; D002254:Carbonates / Q000737:chemistry*; D007834:Lasers; D013058:Mass Spectrometry / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D014131:Trace Elements / Q000032:analysis*
D002254:Carbonates; D014131:Trace Elements