Analysis of isothiazolinone preservatives in household deodorizers and air fresheners through solid-phase extraction and liquid chromatography-tandem mass spectrometry

Isothiazolinone preservatives are known to cause contact dermatitis. Although they are used in household deodorizers and air fresheners, the actual extent of their use remains unclear. In this study, we developed a method to simultaneously analyze five isothiazolinones (2-methyl-4-isothiazilin-3-one: MI, 5-choro-2-methyl-4-isothiazolin-3-one: CMI, benzisothiazolin-3-one: BIT, 2-n-octyl-4-isothiazolin-3-one: OIT, 4,5-dichloro-n-octyl-4-isothiazolin-3-one: 2Cl-OIT) in spray-type household deodorizers and air fresheners. The samples were analyzed through solid-phase extraction and liquid chromatography-tandem mass spectrometry. Three solid-phase extraction cartridges were examined, and good results were obtained for the OASIS HLB Plus LP cartridge. The recoveries and standard deviations for isothiazolinone preservatives extracted using this cartridge were 72-99 and 1.6-6.0%, respectively. In addition, the limit of detection and limit of quantification were as follow: 0.012 and 0.037 mu g/mL for MI, 0.029 and 0.089 mu g/mL for CMI, 0.032 and 0.098 mu g/mL for BIT, 0.013 and 0.040 mu g/mL for OIT, and 0.015 and 0.047 mu g/mL for 2Cl-OIT. Among the 51 analyzed products, only 10 were detected with isothiazolinone compounds. MI and CMI were detected in five products at concentration levels of 0.31-22 and 0.77-95 mu g/mL, respectively, while BIT was detected in the other five products at 2.7-101 mu g/mL.

Automated summary

In this study, a method for simultaneously analyzing five isothiazolinones in spray-type household deodorizers and air fresheners was developed and good results were obtained. Among the 51 analyzed products, only 10 were detected with isothiazolinone compounds, with MI, CMI, and BIT being the most commonly detected at various concentration levels.