Determination of the optimal injection parameters for the SPME Arrow analysis of VOCs
- 1Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
- 2Centre for Water and Environmental Research, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
- 3IWW Water Centre, Moritzstrasse 26, 45476 Mülheim an der Ruhr, Germany
Abstract
The injection step in SPME Arrow-GC-MS analysis is critical for sensitivity, repeatability, and peak shape, but is often less systematically optimized than extraction. In this study, the injection efficiency of SPME Arrow fibers was investigated using 1-methylnaphthalene as a model volatile organic compound. Real-time desorption-and-transfer profiles were recorded to evaluate the effects of liner geometry, carrier-gas flow rate, and column insertion depth for two coatings, PDMS/CWR and PDMS/DVB. Here, desorption denotes analyte release from the coating, while transfer denotes the subsequent transport of the released analyte through the injector and into the column or detector connection. Total peak area was used as a measure of transferred analyte amount, while the half-mass point described transfer kinetics. The results show that SPME Arrow injection is governed by a combined desorption-and-transfer process rather than by thermal desorption alone. For PDMS/CWR, a narrow 1.2 mm i.d. liner markedly improved injection efficiency compared with a conventional 2.0 mm i.d. liner, providing relative desorption-and-transfer response close to 100% over a broad range of carrier-gas flow rates. The narrow liner also reduced half-mass points, indicating faster transfer. For PDMS/DVB, however, the highest total peak areas were obtained with the wider liner at elevated carrier-gas flow rates, although the narrow liner produced faster transfer. These results demonstrate that optimal injection conditions are strongly coating-dependent and cannot be predicted solely from liner diameter or carrier-gas velocity. The study highlights the need to optimize SPME Arrow injection parameters separately for each coating and analytical objective. Both total transferred amount and transfer kinetics should be considered, since the fastest transfer condition does not necessarily provide the highest analyte recovery.
Graphical abstract :
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00216-026-06757-y.
Related
- Magnetite-based SPME-SQT-FAAS for trace chromium determination in rice
- Alternative Equations and 'Pseudo-statistical' Approaches that Enhance the Precision of Initial Rates for the Determination of Kinetic Parameters
- Effect of Low-Frequency Pulsating Water Injection Parameters on Coal Permeability: Quantitative Characterization Experiments and a Field Case Study
- Determination of the Optimal Mixture of Wall Materials for the Encapsulation of Cacao Pod Polyphenols by Spray Drying Using Response Surface Methodology
- Volatilome Characterization of the Flat White Onion of Fara Filiorum Petri (Allium cepa L.) and Its Differentiation from Other Italian White Onions by HS-SPME-GC-MS
BibTeX
@article{stojanovic2026determination,
title = {{Determination of the optimal injection parameters for the SPME Arrow analysis of VOCs}},
author = {Nenad Stojanović and Maik A. Jochmann and Torsten C. Schmidt},
journal = {Analytical and Bioanalytical Chemistry},
year = {2026},
month = aug,
doi = {10.1007/s00216-026-06757-y},
url = {https://doi.org/10.1007/s00216-026-06757-y},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Determination of the optimal injection parameters for the SPME Arrow analysis of VOCs
AU - Nenad Stojanović
AU - Maik A. Jochmann
AU - Torsten C. Schmidt
PY - 2026
DA - 2026/08/31
JO - Analytical and Bioanalytical Chemistry
DO - 10.1007/s00216-026-06757-y
UR - https://doi.org/10.1007/s00216-026-06757-y
AB - The injection step in SPME Arrow-GC-MS analysis is critical for sensitivity, repeatability, and peak shape, but is often less systematically optimized than extraction. In this study, the injection efficiency of SPME Arrow fibers was investigated using 1-methylnaphthalene as a model volatile organic compound. Real-time desorption-and-transfer profiles were recorded to evaluate the effects of liner geometry, carrier-gas flow rate, and column insertion depth for two coatings, PDMS/CWR and PDMS/DVB. Here, desorption denotes analyte release from the coating, while transfer denotes the subsequent transport of the released analyte through the injector and into the column or detector connection. Total peak area was used as a measure of transferred analyte amount, while the half-mass point described transfer kinetics. The results show that SPME Arrow injection is governed by a combined desorption-and-transfer process rather than by thermal desorption alone. For PDMS/CWR, a narrow 1.2 mm i.d. liner markedly improved injection efficiency compared with a conventional 2.0 mm i.d. liner, providing relative desorption-and-transfer response close to 100% over a broad range of carrier-gas flow rates. The narrow liner also reduced half-mass points, indicating faster transfer. For PDMS/DVB, however, the highest total peak areas were obtained with the wider liner at elevated carrier-gas flow rates, although the narrow liner produced faster transfer. These results demonstrate that optimal injection conditions are strongly coating-dependent and cannot be predicted solely from liner diameter or carrier-gas velocity. The study highlights the need to optimize SPME Arrow injection parameters separately for each coating and analytical objective. Both total transferred amount and transfer kinetics should be considered, since the fastest transfer condition does not necessarily provide the highest analyte recovery. Graphical abstract : Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1007/s00216-026-06757-y.
SN - 1618-2642
SN - 1618-2650
ER -