Real-Time Monitoring of Fragrance Release from Cotton Towels by Low Thermal Mass Gas Chromatography Using a Longitudinally Modulating Cryogenic System for Headspace Sampling and Injection

Abstract

An innovative headspace sampling and injection system for gas chromatography was designed using a longitudinally modulating cryogenic system mounted around the sampling loop of a two-position loop injector. The setup was hyphenated to a fast low thermal mass gas chromatograph, allowing transient concentrations of semivolatile analytes to be monitored in real time with a time resolution of 4.5 min. The performance of the instrument, and in particular its cryotrapping efficiency, was characterized using a mixture of long-chain alkanes, methyl esters, ethyl esters, and alcohols of different volatilities. The device was found to be ideally suited to the analysis of semivolatile compounds with boiling points ranging between 190 and 320 degrees C, which are typical for a majority of perfumery raw materials. The new instrument was successfully used to monitor the release of eight odorant compounds from cotton towels to which fabric softener had been applied that alternatively contained the fragrance in free form or in microencapsulated form. The analytical results, unprecedented in their level of precision and time resolution for such an application, evidenced the major impact of microencapsulation technology on the kinetics of fragrance release during the drying of the towels and on the triggering of additional fragrance release by applying mechanical stress to the fabric to rupture the microcapsule walls.

Preparation and characteristics of nanocapsules containing essential oil for textile application

“…It has been proved that the aroma perception is maintained for several days in fabrics if fabrics impregnated with capsules containing perfume and the capsules continue to emit aroma for up to five wash cycles. [11][12][13] Fragrance encapsulated in small particles (nanometer range) and narrow dispersion are preferred for use in textiles as they can provide a strong adhesive force and interact with the fibre due to their large surface area. [14] Furthermore, the smaller the capsules the greater the covering of the product and the longer the fragrance will last because it takes longer for the capsules to be ruptured by physical pressure.…”

Scent properties by natural fragrance microencapsulation for footwear applications

“…In the case of the MF microcapsules, the release of the fragrance would be based on other mechanisms such as diffusion through the polymeric microcapsule wall. Other authors have reported this kind of release due to the permeability of the shell and it is triggered by rubbing caused during the wearing of the footwear …”

In Situ Measurement and Monitoring of Diphenyl Disulfide in Ethanol Solution by SERS

“…In recent years, the widespread use of real-time monitoring technology has included spectroscopic methods [5], chromatography, and chromatography coupled with spectral detection [6][7]. At present, gas chromatography is the most commonly used real-time on-line analysis technology [8].…”