An UPLC-Orbitrap MS system was exploited to develop and validate a method for the simultaneous determination of 11 water-soluble azo dyes (Acid Yellow 17, Acid Red 14, Acid Red 26, Acid Red 73, Acid Orange 52, Acid Orange 7, Acid Orange 12, Acid Yellow 36, Acid Orange 5, Acid Red 88 and Acid Red 9) in soft drinks. Three pairs of isomers and four disulphonated azo dyes were among a total of 11 water-soluble azo dyes obtained and purified using an SPE cartridge. They were well separated using optimized UPLC conditions with a RP18 column and a MS detector with a compatible mobile phase system. All these dyes were detected by the Orbitrap XL mass spectrometer in negative ion mode. HCD tandem MS fragment ions are first reported in this paper, and these fragment ions can be used for identification of isomers of azo dyes. According to SANCO/10684/2009, one quasi-molecular ion in full scan mode as quantification ion and one or two HCD tandem MS fragment ions as identification ions are required for compound confirmation. Matrix-matched calibration was employed for quantification. The linear matrix-matched calibration for the 11 dyes was in the range 5-200 ng g(-1) with correlation coefficients (r) of 0.9939-0.9988. Recoveries were 68.9-110.8% with coefficients of variation of 0.9-12.0%. Depending on the dye and matrix involved, the LODs were between 1.0 and 3.2 ng g(-1) and LOQs were between 5.2 and 9.8 ng g(-1).

An improved method with a simple and rapid solid phase extraction procedure for the simultaneous determination of nine common polybrominated diphenyl ethers (PBDEs) in human serum has been established using gas chromatography-negative chemical ionization mass spectrometry. Purification and lipid removal were carried out directly on a solid phase extraction column using water, concentrated sulfuric acid and 10% aqueous methanol, followed by elution with dichloromethane. The eluent was concentrated and then loaded on a short capillary column to detect PBDEs. The results of the spike recovery experiments in fetal bovine serum showed that the average recoveries of the target compounds were between 80.5% and 110.2%. The intraday relative standard deviations were between 1.2% and 9.8%, and the interday relative standard deviations were between 1.8% and 11.1%. The limits of detection for tribromo to nonabromo diphenyl ethers in fetal bovine serum were in the range of 0.208-0.653 ng L À1 and the limits of quantification were in the range of 0.653-1.000 ng L À1 . The limit of quantification for BDE-209 was 10.038 ng L À1 and the correlation coefficients in the linear range were greater than 0.997. This method showed good accuracy and precision, and was suitable for the determination of PBDEs in umbilical cord blood samples.