High-yield UV-photochemical vapor generation of iron for sample introduction with inductively coupled plasma optical emission spectrometry.
A novel approach to the generation of volatile iron compounds (likely the pentacarbonyl) with high efficiency is described, wherein solutions containing either Fe(2+) or Fe(3+) and low molecular weight organic acids such as formic, acetic or propionic are exposed to a UV source. An optimum generation efficiency of 60 +/- 2% was achieved in 50% formic acid at pH 2.5 with an irradiation time of 250 s by use of a 17 W low-pressure mercury grid lamp. Compared to conventional solution nebulization, sensitivity and limit of detection were improved 80- and 100-fold, respectively, at the 238.204 nm Fe II emission line. A precision of 0.75% RSD was achieved at a concentration of 100 ng/mL. Photochemical vapor generation sample introduction was used for the determination of trace iron in several environmental Certified Reference Materials, including National Research Council Canada DORM-3 fish muscle tissue, DOLT-3 and DOLT-4 fish liver tissues, and SLRS-5 river water, providing analytical results in excellent agreement with certified values based on a simple external calibration.
Zheng
Chengbin
C
College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, China.
Sturgeon
Ralph E
RE
Brophy
Christine S
CS
He
Shaopan
S
Hou
Xiandeng
X
D019342:Acetic Acid / Q000737:chemistry; D004785:Environmental Pollutants / Q000032:analysis; D005561:Formates / Q000737:chemistry; D005740:Gases / Q000737:chemistry*; D007501:Iron / Q000032:analysis*; D055668:Photochemical Processes; D011422:Propionates / Q000737:chemistry; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014466:Ultraviolet Rays
D004785:Environmental Pollutants; D005561:Formates; D005740:Gases; D011422:Propionates; C030544:formic acid; D007501:Iron; C029658:propionic acid; D019342:Acetic Acid