Catalytic Oxygenation-Mediated Extraction as a Facile and Green Way to Analyze Volatile Solutes

Abstract

Sparging-based methods have long been used to liberate volatile organic compounds (VOCs) from liquid sample matrices prior to analysis. In these methods, a carrier gas is delivered from an external source. Here, we demonstrate “catalytic oxygenation-mediated extraction” (COME), which relies on biocatalytic production of oxygen occurring directly in the sample matrix. The newly formed oxygen (micro)­bubbles extract the dissolved VOCs. The gaseous extract is immediately transferred to a separation or detection system for analysis. To start COME, dilute hydrogen peroxide is injected into the sample supplemented with catalase enzyme. The entire procedure is performed automaticallyafter pressing a “start” button, making a clapping sound, or triggering from a smartphone. The pump, valves, and detection system are controlled by a microcontroller board. For quality control and safety purposes, the reaction chamber is monitored by a camera linked to a single-board computer, which follows the enzymatic reaction progress by analyzing images of foam in real time. The data are instantly uploaded to the internet cloud for retrieval. The COME apparatus has been coupled on-line with the gas chromatography electron ionization mass spectrometry (MS) system, atmospheric pressure chemical ionization (APCI) MS system, and APCI ion-mobility spectrometry system. The three hyphenated variants have been tested in analyses of complex matrices (e.g., fruit-based drinks, whiskey, urine, and stored wastewater). In addition to the use of catalase, COME variants using crude potato pulp or manganese­(IV) dioxide have been demonstrated. The technique is inexpensive, fast, reliable, and green: it uses low-toxicity chemicals and emits oxygen.

Simultaneous Sensing of Multiplex Volatile Organic Compounds by Adsorption and Plasmon Dual-Induced Raman Enhancement Technique

“…However, most VOCs are non-reactive and are diverse in actual samples, which make VOCs detection very changeable at present . Over the past decades, a variety of detection technologies have been developed for VOCs sensing, including mass spectrometry, electrochemical sensors, gravimetric-based sensors, and some others. − These methods have greatly contributed to the VOCs’ detection and analysis. However, most of these approaches suffer from issues of complicated equipment, lack of well-trained personnel, and long analysis time.…”