RAPID COMMUNICATION Sol-gel-based SPME fiber as a reliable sampling technique for studying biogenic volatile organic compounds released from Clostridium tetani Masoud Ghader 1,2 & Nader Shokoufi 1 & Ali Es-haghi 2 & Kazem Kargosha 1 Received: 28 June 2017 /Revised: 15 September 2017 /Accepted: 25 September 2017 # Springer-Verlag GmbH Germany 2017 Abstract A novel and efficient headspace solid-phase microextraction (HS-SPME) method, followed by gas chro- matography mass spectrometry (GC-MS), was developed to study volatile organic compounds (VOCs) emerging from mi- croorganisms. Two homemade SPME fibers, a semi-polar poly (dimethylsiloxane) (PDMS) fiber, and a polar polyethyl- ene glycol (PEG) fiber, along with two commercial fibers (PDMS and PDMS/DVB) were used to collect VOCs emerg- ing from Clostridium tetani which was cultured in different media. The adsorbed VOCs were desorbed and identified, in vitro, using GC-MS. The adsorption efficiency was im- proved by optimizing the time duration of adsorption and desorption. About 50 components were identified by the pro- posed method. The main detected compounds appeared to be sulfur containing compounds such as butanethioic acid S- methyl ester, dimethyl trisulfide, and dimethyl tetrasulfide. These volatile sulfur containing compounds are derived from amino acids containing the sulfur element, which probably coexist in the mentioned bacterium or are added to the culture media. The developed HS-SPME-GC-MS method allowed the determination of the chemical fingerprint of Clostridium tetani volatile constituents, and thus provides a new, simple, and reliable tool for studying the growth of microorganisms. Keywords Sol-gel . HS-SPME . Volatile organic compounds . Clostridium tetani . GC-MS Introduction Bacterial species release trace amounts of biological volatile organic compounds (VOCs). Bacterial VOCs have been used as biomarkers for bacterial detection. They have been consid- ered in sensitive and specific detections in human specimens (in vivo) as well as culture media (in vitro), and have allowed non-invasive monitoring. Bacterial VOCs have opened a new frontier for developing markers in larger groups of bacteria, as efficient techniques for the diagnosis of bacterial infections [1]. There are many reported works on the identification of volatiles released from diverse species of pathogenic bacteria [2–5]. The bacteria species emerge different kinds of VOCs with different patterns which reflect the promotion step of bacterial growth and their metabolic pathway [6–8]. Sophisticated technologies such as gas chromatography mass spectrometry (GC-MS), different types of mass spec- trometry and electronic noses (E-Noses) have been widely applied for studying the VOCs [6, 8]. Among these tech- niques, GC-MS is the most commonly used one due to its simplicity and reliability. Since bacterial VOCs have complicated compositions with different chemical structures and polarities, an efficient and suitable sampling technique is required for their sampling without sample contamination. Nowadays, several sampling Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00216-017-0675-1) contains supplementary material, which is available to authorized users. * Ali Es-haghi a.eshaghi@rvsri.ac.ir 1 Faculty of Clean Technologies, Chemistry & Chemical Engineering Research Center of Iran (CCERCI), P.O. Box 14968-13151, Tehran, Iran 2 Department of Physico Chemistry, Razi Vaccine & Serum Research Institute (RVSRI), Agricultural Research, Education and Extension Organization (AREEO), P.O. Box 31975/148, Karaj, Iran Anal Bioanal Chem DOI 10.1007/s00216-017-0675-1