title: Analysis of Acidic Tar Dyes in High Protein Food: Effect of pH of Column Loading Solution for Clean-Up.
abstract: The effect of pH of the clean-up process in the analysis of 11 permitted tar dyes in high protein food was investigated by using a handmade polyamide column (PA column) and Oasis HLB. Boiled fish paste spiked with the 11 dyes was extracted with appropriate solvents and the pH of the extract was adjusted to 3.0-7.0 in increments of 0.5, followed by clean-up with the PA column. At pH 3.0-5.5, precipitate formed in the extract clogged the column, and the recoveries of R3, R104 and R105 were 26-68%. At pH 6.0-7.0, clogging was not observed and the recoveries of the 3 dyes were somewhat higher, at 38-79%. The recoveries of other dyes were more than 80% at pH 3.0-7.0. With Oasis HLB, column loading was conducted at pH 11.0, and the recoveries of the 3 dyes improved to 70-83%. In conclusion, all 11 dyes could be cleaned-up with the PA column and Oasis HLB and the recoveries exceeded 70%.
authors.affiliation: Tokyo Metropolitan Institute of Public Health.
authors.forename: Asa
authors.initials: A
authors.lastname: Osuga
authors.forename: Yoko
authors.initials: Y
authors.lastname: Uematsu
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yamajima
authors.forename: Takushi
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Shoichi
authors.initials: S
authors.lastname: Tahara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyakawa
authors.forename: Toshiko
authors.initials: T
authors.lastname: Mizumachi
authors.forename: Kimio
authors.initials: K
authors.lastname: Monma
mesh_terms: D005396:Fish Products / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D005505:Food Coloring Agents / Q000032:analysis* / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D008461:Meat Products / Q000032:analysis*; D009757:Nylons; D052616:Solid Phase Extraction / Q000379:methods; D012996:Solutions; D013638:Tars / Q000032:analysis* / Q000302:isolation & purification*
chemical_list: D005505:Food Coloring Agents; D009757:Nylons; D012996:Solutions; D013638:Tars