Search

A method was developed for the determination of total arsenic in foods using flow injection on-line sorption coupled with hydride generation atomic fluorescence spectrometry (HG-AFS) using a cigarette filter as the sorbent material. After reducing As(V) to As(III) by using L-cysteine, the determination of total arsenic was achieved through on-line formation and retention of the pyrrolidine dithiocarbamate arsenic complex (As(III)-PDC) on the cigarette filter, which was packed in the pre-concentration column and total arsenic was determined by HG-AFS. The analytes were eluted with 1.68 mol l(-1) HCl from the sorbent material. With consumption of 22 ml of the sample solution, an enrichment factor of 25.6 was obtained at a sample throughput of 11.6 h(-1). The detection limits (3 standard deviations) and the precision (relative standard deviation) in foods ranged from 2.5 to 9.9 ng g(-1) and from 1.1 to 2.2%, respectively. The method was used to determine arsenic in carrot, mushroom, chicken tissue, cod fish, rice, common carp and shrimp.

A fiber-optic measurement technique is developed for estimating the pressure inside a piston cylinder cell up to approximately 4 GPa, based on the pressure-induced R1 fluorescence line shift of ruby (ruby scale). Ruby scale and a conventional technique (calibration on phase transitions of bismuth) were simultaneously applied to the cell filled with a pressure transmitting medium of isopropyl alcohol. The pressure readings of the two methods were consistent with each other, and no pressure gradient was observed. The ruby scale has the advantages of real time estimation and easy installation in a small space. Because of these advantages, three fibers were simultaneously introduced in the sample space at the same time, and pressure distribution was measured for Fluorinert (FC70:FC77=1:1), Daphne oil 7373, and Fomblin oil (YHVAC 13014).