Detection of Reactive Dyes from Dyed Fabrics after soil degradation via QuEChERS extraction and Mass Spectrometry

Landfill is becoming a common method to dispose of unwanted or used clothes. The dyes and finishes present on these garments can be a new source of pollution that can potentially leach into soil. A set of knitted cotton fabrics dyed with four common reactive dyes used in the textile industry, C.I. Reactive Orange 35 (RO35), C.I. Reactive Blue 49 (RB49), C.I. Reactive Black 5 (RBlk 5), and C.I. Reactive Blue 19 (RB19), were studied by the ASTM D5988-03 method to determine potential degradation products in landfills. A modified QuEChERS method was used to extract all reactive dyes and derivatives from soil samples in which knitted dyed cotton fabrics were degraded. All extracts were characterized by high-resolution mass spectrometry (HRMS) by using a Quadrupole Time-Of-Flight (Q-TOF) mass spectrometer, where native dyes and their hydrolysis products were identified in soil samples from 45 and 90 day degradation experiments. Four potential degradation derivatives were found and molecular formulas were proposed based on exact mass measurements. These results suggested that traces of reactive dyes and their derivatives from degraded knitted cotton fabrics can be extracted and detected by using a modified QuEChERS method and HRMS.