Direct Determination of Lead in Foods by Solid Sampling Electrothermal Vaporization Atomic Fluorescence Spectrometry

Abstract

A solid sampling method for the determination of lead in foods (including grains, vegetables and seafoods) using electrothermal vaporization atomic fluorescence spectrometry was established. The method introduced samples using electrothermal vaporization by quartz furnace and used on-line ashing and vaporization to remove matrix interferences for the specific trap of lead. It was proven by the certified reference material (CRM) and the recovery rate of the standards that the electrothermal vaporization was stable and there was no effect for sampling difference. The best operating program and parameters for the new method included ashing (850 C, 160 s), vaporization and trap (1050 C, 80 s; 800 C, 10 s), release (800 C, 10 s), and mixed Ar + H2 (85:15%, v/v) as carrier gas with flow rate of 500 mL/min. The relative standard deviations of repeated Pb measurements in CRMs were all below 5.0%, and the recovery rate ranged from 90.0 -110.0%. The limit of detection (LOD) for the new method was 3.0 pg and the limit of quantification (LOQ) was 10.0 pg. The total time of analysis was less than 6 min. No significant differences existed between the results measured by the new method and microwave ICP-MS.

Modular Assembly of Tunable Fluorescent Chemosensors Selective for Pb2+ and Cu2+ Metal Ions via the Multicomponent Castagnoli‐Cushman Reaction

“…With the use of selective fluorometric probes for metal ions, coupled with fluorimetric detection, these analyses can be performed in an express, non‐destructive manner using portable devices . Another advantage of fluorometric techniques is their adaptability to the direct flow analysis format . Thus, it is unsurprising that the development of increasingly selective and sensitive fluorometric probes for the detection and quantification of metal ions has been attracting considerable attention…”