Determination of Ni and V in Crude Oil Samples Encapsulated in Zr Xerogels by Laser-Induced Breakdown Spectroscopy

Abstract

Encapsulation of samples in Zr xerogels has been implemented for the elemental analysis of crude oils using laserinduced breakdown spectroscopy. Pellets produced from xerogels proved to be durable and homogeneous, and they allow for ablation of the samples without splatters. Ni and V present in Venezuelan crude oil were used as probe elements, and Yttrium was used as an internal standard to take into account the fluctuations in the amount of ablated material. All of the calibration curves obtained were described by high correlation coefficients, r2 > 0.990. Detection limits of 7 and 4 μg g−1 for V and Ni were estimated, respectively. V/(V + Ni) quotients showed high values of >0.8. The accuracy of the method was assessed by analyzing standard reference materials (SRM 1084a and 1085b). The measured values of V and Ni in the SRM agreed well with the certified values at the 95% confidence level.