Sociedade Brasileira de Espectrometria de Massas – BrMASS
Simultaneous determination of disperse dyes and aromatic
amines derivatives in superficial water by LC/MS/MS
Bianca Ferreira da Silva a, Thiago Mescoloto Lizier e Maria V. B. Zanoni
a
*e-mail: biribisfs@gmail.com
Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho,
Araraquara, SP, Brasil
Around 2000 different dyes are widely used in textile, leather, plastics, paper, cosmetic and
food industries. In this context, azo dyes include a very important family of hydrophobic
dyes known as disperse dyes and have been identified as aquatic contaminants. In view of
genotoxicity concerns arising from the use of certain aromatic amines in azo dye
manufacturing or even in their degradation. It has been explored dyes degradation and the
main products obtained are their precursor, aromatic amines. Aromatic amines can enter
the aqueous environment as precursors from the synthesis of azo dyes and nitroaromatic
compound reductions. Since they have been designated as high priority pollutants, their
presence in the environment must be monitored at low concentration. Around 30 aromatic
amines are of great concern. In general, the amines cited by IARC are limited to ppb levels
in natural waters, which demands sensitive analytical methods, such as liquid
chromatography coupled to a tandem mass spectrometry. In the present work, a
simultaneously method was developed to determine 19 disperse dyes (D.Blue291,
D.Blue56, D.Blue60, D.Orange1, D.Orange25, D.Orange3, D.Orange30, D.Orange37,
D.Red1, D.Red13, D.Red60, D.Red82, D.Violet93, D.Yellow3, D.Yellow7, D.Yellow9,
SudanI, SudanII, SudanIII and Sudan Orange G) and 30 aromatic amines (o-Dianisidine, oAnisidine, o-Tolidine, o-Toluidine, Phenylenediamine, 2,4-Diaminetoluene, 2,5methoxymethylaniline, 2,6-dimethylaniline, 2-methyl-5-nitroaniline, 2-methylaniline, 2naphthylamine, 3,3-dichlorobenzidine, 4,4-diaminodimethane, 4,4-diaminodiphenyl, 4,4methylenebis, 4,4-oxydianiline, 4-aminoacetanilide, 4-aminoazobenzene, 4-chloro-2methylaniline, 4-chloroaniline, 4-methoxyphenol, 4-methylthioaniline, 4-nitroaniline, 5aminobiphenyl, Aniline, Benzidine, Hydrazobenzol, Isoquinoline, Methylanthranilate, oAminoazotolueno, Auramine). Liquid chromatography was carried out using a Phenomenex
PFP column 5µm (150 x 4.6mm) during a gradient elution. Due to the high affinity of the
disperse dyes to the column, a flow of 1.5mL was used. The solvents were acetonitrile and
water, both containing 0.1% of formic acid. The total analysis was performed in 30
minutes. The MS/MS analysis were performed used the MRM mode. Two transitions of
each compound were used to monitor all analytes. The MRM conditions were obtained by
the infusion of each compound prepared individually. Solid phase extraction (SPE) and
liquid-liquid extraction (LLE) were performed to evaluate the recovery of the compounds in
tap water and pure water. The recoveries studies were performed by spiking the samples
and the results showed that the LLE using dichloromethane:methanol (2:1, v/v) was the
best extraction method to obtain all compound at once. Including all compounds, the
recovery range was 50-120% in tap water and for pure water from 20 to 140%. SPE
extraction showed poorly retention of disperse dyes and only a few aromatic amines could
be determined. The limits of detection (LOD) and quantification (LOQ) were ranged from
0.1 – 5 ppb and 1 – 20 ppb, respectively. It has been noted the aromatic amines present
lower LOD and LOQ than the disperse dyes. Therefore, a LLE coupled to LC/MS/MS
analysis allowed the detection of a very low concentration of disperse dyes and aromatic
amines in one injection. The methodology showed a promising application in analysis of
environmental samples. Preliminary studies were carried out with river water and waste
water samples and the method has shown high efficiency and reproductibility.