LAUSR

An effective, rapid and inexpensive method without chromatographic separation was proposed for the determination of thimerosal (THM) and inorganic mercury (IHg) in vaccine samples, based on Fe3+-induced degradation of THM in a commercially available atomic fluorescence spectrometer (AFS). In the proposed method, inorganic mercury was measured at a low concentration of KBH4 (0.005%, m/v) in the absence of Fe3+, while the total mercury (THg) was determined by measuring the same fluorescence signals of IHg and THM, which was effectively degraded and reduced in the presence of 10 mg L−1 Fe3+ and a relatively high concentration of KBH4 (1.0%, m/v). Then, the concentration of THM can be obtained by subtracting IHg concentration determined in the absence of Fe3+ from THg concentration in the presence of Fe3+. The parameters influencing mercury determination were optimized in detail, including Fe3+ concentration, the concentration of the KBH4 reductant and HCl carrier, and the carrier gas flow rate. Under the optimized conditions, the limits of detection for THM and IHg were 0.03 μg L−1 and 0.02 μg L−1, respectively. Spiked commercial vaccine samples including hepatitis-B and rabies vaccines were analyzed. Satisfactory recoveries were obtained for both THM and IHg.