Absorption Spectrophotometric Method For Determination Research Articles

Atomic Absorption Spectrophotometric Method for Determination of Polydimethylsiloxane Residues in Pineapple Juice: Collaborative Study

An atomic absorption spectrophotometric method for determination of polydimethylsiloxane (PDMS) residues in pineapple juice was collaboratively studied by 9 laboratories. PDMS residues are extracted from pineapple juice with 4-methyl-2-pentanone and the extracted silicone is measured by atomic absorption spectrophotometry using a nitrous oxide/acetylene flame. Collaborators analyzed 5 samples including 1 blind duplicate. Reproducibility relative standard deviations (RSDR) were 13.1% at 31 ppm, 6.9% at 18 ppm, 14.8% at 7.9 ppm, and 16.1% at 4.9 ppm PDMS. The method has been approved interim official first action by AOAC.

Variations of total phosphorus and nitrogen levels in rain water.

We have previously proposed an atomic absorption spectrophotometric method for determination of total phosphorus in water. In this paper, the proposed method was applied to the rain water collected for a year (July 1984-June 1985) from three different locations : Kobe, Amagasaki and Miki. The concentrations of total nitrogen in the water samples were also determined by a conventional method as described in the Official Gazette. Kobe, Amagasaki and Miki, situated in the southern part of Hyogo prefecture in Japan, were chosen as representatives of residential, industrial and agricultural areas, respectively. The water samples from Miki contained significantly higher concentrations of total phosphorus than those from Kobe and Amagasaki, this might be due to fertilizer used in the agricultural area. In contrast, the concentrations of total nitrogen in the samples from Amagasaki were significantly higher than those from the other two locations, which suggested that the nitrogen in rain water might be derived from air pollution with nitrogen oxides owing to motor vehicles and factories in the industrial area.

Atomic Absorption Spectrophotometric Method for Determination of Water-Soluble Copper in Water-Insoluble Copper Fungicides: CIPAC Collaborative Study. Comparison with Bathocuproine Method

Abstract An atomic absorption spectrophotometric (AAS) method was collaboratively studied by 8 laboratories from Africa, the United States, Australia, and Europe. The samples were dispersed in deionized water. After centrifuging and filtering, the water-soluble copper in the filtrate was acidified and measured by atomic absorption spectrophotometry, in an airacetylene flame, at 324.7 nm. The results from 7 laboratories were satisfactory and no unfavorable comments were received. Repeatability standard deviations ranged from 0.005 to 0.023, and reproducibility standard deviations ranged from 0.012 to 0.062. When compared with the bathocuproine method, the difference in bias between both methods is not significant. They were both adopted as full CIPAC methods, with the bathocuproine method as the referee method. Both methods have been adopted official first action.