title: Photoacoustic spectroscopic studies on the solid phase cell with a differential type microphone using a diode laser as radiation source.
abstract: The design and applications of the solid phase photoacoustic cell with a differential type microphone are described. This cell has higher sensitivity and reproducibility relative to a cell without a differential microphone. The method has been applied to the determination of phosphate ion in water samples. The detection limit for phosphate ion concentrated from 22.5 ml of sample solution on a membrane filter as molybdophosphate-n-dodecyltrimethylammonium bromide was 3.0 ng PO(3-)(4)/ml and the coefficient of variation for five measurements at 20 ng PO(3-)(4)/ml of phosphate ion was 3% using a diode laser (30 mW, 826 nm) as radiation source. The calibration graph for phosphate ion was linear over the range 5-50 ng PO(3-)(4)/ml.
authors.affiliation: Department of Materials Science and Engineering, Faculty of Engineering, Yamagata University, Jonan-4, Yonezawa, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Shida
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Oikawa