A new strategy of solution calibration in laser ablation inductively coupled plasma mass spectrometry for multielement trace analysis of geological samples

Because multielement trace analysis by laser ablation inductively coupled p lasma mass spectrometry (LA-ICP-MS) is often limited by the lack of suitabl e reference materials with a similar matrix composition, a novel quantifica tion strategy using solution calibration was developed. For mass spectromet ric multielement determination in geological samples a quadrupole-based LA- ICP-MS is coupled with an ultrasonic nebulizer (USN). In order to arrange m atrix matching the standard solutions are nebulized with a USN during solut ion calibration and simultaneously a blank target (e.g. lithium borate) is ablated with a focused laser beam. The homogeneous geological samples were measured using the same experimental arrangement where a 2% nitric acid is simultaneously nebulized with the USN. Homogeneous targets were prepared fr om inhomogeneous geological samples by powdering, homogenizing and fusing w ith a lithium berate mixture in a muffle furnace at 1050 degrees C. Further more, a homogeneous geological glass was also investigated. The quantificat ion of analytical results was performed by external calibration using calib ration curves measured on standard solutions. In order to compare two diffe rent approaches for the quantification of analytical results in LA-ICP-MS, measured concentrations in homogeneous geological targets were also correct ed with relative sensitivity coefficients (RSCs) determined using one stand ard solution only. The analytical results of LA-ICP-MS on various geologica l samples are in good agreement with the reference values and the results o f other trace analytical methods. The relative standard deviation (RSD) for trace element determination (N = 6) is between 2 and 10%.