SPME Fiber Evaluation for Volatile Organic Compounds Extraction from Acerola

Abstract

Volatile organic compounds (VOCs) were isolated from acerola fruits (Malpighia emarginata D.C.), by means of different solid phase microextraction (SPME) fibers. For the extraction, the headspace SPME method was used, identifying the VOCs by gas chromatography (GC) with mass spectrometry (MS). The objective of this work was to evaluate the efficiency of SPME fibers and determine the best conditions for extracting VOCs from acerola fruit. The investigated conditions were: extraction time (20, 30 and 40 min), extraction temperature (25, 45 and 65 o C) and agitation (0, 50 and 100 rpm). Of the evaluated fibers, polydimethylsiloxane (PDMS)/divinylbenzene (DVB) extracted the highest number of VOCs, most belonging to terpene, carboxylic acids and hydrocarbons. According to the investigated conditions, most compounds were obtained with an extraction time of 20 min, extraction temperature 65 o C, and no agitation. Compounds cumene, o-xylene, thymol, m-cymene, o-cymene, 2-methyl-1,3-butadiene, anethol, 3-buten-2-one and methyl octadecanoic ester were responsible for the volatile profile of acerola.

Time‐of‐flight secondary ion mass spectrometry and gas chromatography–mass spectrometry studies of alkanethiol self‐assembled monolayers on nanoporous gold surfaces

“…DVB‐Carboxen‐PDMS fiber showed higher extraction efficiency for most detected compounds (at different extraction times) compared with that of Carboxen‐PDMS. This observation agrees with the findings of many other studies, where DVB‐Carboxen‐PMDS fiber was used for the extraction of volatile and semivolatile compounds with different molar weights and polarities 31–34 . Porous gold SPME (PG‐SPME) has shown an increase in the peak areas of almost all extracted compounds compared with that of the commercial fibers (Table 1).…”

“…The high extraction efficiency of the nanoporous gold SPME is due to the high affinity of alkanethiols, dialkyl sulfides, and dialkyl disulfides to gold (see Table 1). The intensities of detected dialkyl sulfides and dialkyl disulfides were higher than those of alkanethiols, as alkanethiols are more favorable to be adsorbed (at high temperatures) on gold as dialkyl disulfides 29–31 …”

“…This observation agrees with the findings of many other studies, where DVB-Carboxen-PMDS fiber was used for the extraction of volatile and semivolatile compounds with different molar weights and polarities. [31][32][33][34] Porous gold SPME (PG-SPME) has shown an increase in the peak areas of almost all extracted compounds compared with that of the commercial fibers (Table 1). Alkanethiols, dialkyl sulfides, and dialkyl disulfides reached a state of equilibrium after 40 min of using the PG-SPME, which is faster than the tested commercial SPME fibers because of the high affinity of sulfur-containing compounds to gold.…”

“…The intensities of detected dialkyl sulfides and dialkyl disulfides were higher than those of alkanethiols, as alkanethiols are more favorable to be adsorbed (at high temperatures) on gold as dialkyl disulfides. [29][30][31] Dialkyl disulfides were detected by using all the SPME fibers (PG-SMPE and commercial SPME fibers), except hexyl-dodecydisulfide, which was extracted only by PG-SPME. We assume that dialkyl disulfides were formed due to many factors including dimerization of the alkanethiols on the gold surface, heating, and stirring of alkanethiol mixture during the extraction and/or during thermal desorption of SAMs in GC injector.…”

CG-MS/SPME as a Complimentary Tool to Histochemistry in the Study of the Influence of Water Regime on the Physiology of Callistemon viminalis

“…The fibers were then transferred to the CG/MS injector, where they remained in the equipment for 5 minutes. 18,19,20 A gas chromatograph (Trace GC Ultra) equipped with a mass spectrometer (Polaris Q, Thermo Scientific, San Jose, USA) and an injector split/ splitless on splitless mode was used as an ion-trap type analyser. Helium gas (1 mL min -1 flow) was used with a HP-5 MS capillary column (5% phenyl and 95% methylpolysiloxane); 30 m x 0,25 mm x 0,25 μm (Agilent Technologies INC, Munich, Germany).…”