Solid phase dynamic extraction automated

Use of Automated Solid Phase Dynamic Extraction (SPDE)/GC-MS and Novel Macros in the Search for African Elephant Pheromones ... 

Abstract A relatively small number of mammalian pheromones has been identified, in contrast to a plethora of known insect pheromones, but two remarkable Asian elephant/insect pheromonal linkages have been elucidated, namely, (Z)-7-dodecen-1-yl acetate and frontalin. In addition, behavioral bioassays have demonstrated the presence of a chemical signal in the urine of female African elephants around the time of ovulation. Our search for possible ovulatory pheromones in the headspace over female African elephant urine has revealed for the first time the presence of a number of known insect pheromones. This search has been facilitated by the use of a powerful new analytical technique, automated solid phase dynamic extraction (SPDE)/GC-MS, as well as by novel macros for enhanced and rapid comparison of multiple mass spectral data files from Agilent ChemStation . This chapter will focus on our methodologies and results, as well as on a comparison of SPDE and the more established techniques of solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE). 

Automated Solid Phase Dynamic Extraction (SPDE)... 

Bicchi, C., Cordero, C., Liberto, E., Rubiolo, P. and Sgorbini, B. (2004) Automated headspace solid-phase dynamic extraction to analyse the volatile fraction of food matrices. J. Chromatogr. A 1024, 217-226. 

Lipinski, J. (2001) Automated solid phase dynamic extraction-Extraction of organics using a wall coated syringe needle. Fresenius J. Anal. Chem. 369, 57-62. 

Musshoff, F., Lachenmeier, D.W., Kroener, L. and Madea, B. (2002) Automated headspace solid-phase dynamic extraction for the determination of amphetamines and synthetic designer drugs in hair samples. J. Chromatogr. A 958, 231-238. 

Goodwin, T.E., Brown, P., Eggert, M., Evola, M., House, S., Morshedi, G., Weddell, M., Chen, J., Jackson, S.R., Aubut, Y., Eggert, J., Schulte, B.A. and Rasmussen, L.E.L. (2007) Use of automated solid phase dynamic extraction (SPDE)/GC-MS and novel macros in the search for African elephant pheromones. In J. Hurst, R. Beynon C. Roberts and T. Wyatt (Eds.), Chemical Signals in Vertebrates 11. Springer Press, New York, pp. 20-29. 

Musshoff, F. Lachenmeier, D. Kroener, L. Madea, B. (2003). Automated Headspace Solid-Phase Dynamic Extraction for the Determination of Cannabinoids in Hair Samples. Forensic Sci Int, Vol.133, pp. 32-38, ISSN 03790738. 

There are basically three methods of liquid sampling in GC direct sampling, solid-phase extraction and liquid extraction. The traditional method of treating liquid samples prior to GC injection is liquid-liquid extraction (LLE), but several alternative methods, which reduce or eliminate the use of solvents, are preferred nowadays, such as static and dynamic headspace (DHS) for volatile compounds and supercritical fluid extraction (SFE) and solid-phase extraction (SPE) for semivolatiles. The method chosen depends on concentration and nature of the substances of interest that are present in the liquid. Direct sampling is used when the substances to be assayed are major components of the liquid. The other two extraction procedures are used when the pertinent solutes are present in very low concentration. Modem automated on-line SPE-GC-MS is configured either for at-column conditions or rapid large-volume injection (RLVI). 

If the analytes of interest are volatile or semivolatile, solvent extraction is not always necessary, and head-space techniques (HS) can be applied for the analysis, typically utilizing GC as the final analytical step. HS analysis can be defined as a vapor-phase extraction, involving ftrst the partitioning of analytes between a non-volatile liquid or solid phase and the vapor phase above the liquid or solid. The vapor phase is then transferred further and either analysed as vapor or (ad)sorbed to an (ad)sorbent. The head-space techniques have been widely utilized in the analysis of volatiles, such as fi agrances and aroma compounds, in various food and agricultural samples (81-84). The dynamic head-space (DHS), or purge-and-trap technique, is easily coupled on-line with GC. In an on-line system, desorption of trapped analytes for subsequent analysis is usually performed using on-line automated thermal desorption (ATD) devices. 

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