International Journal for Ion Mobility Spectrometry

Mauruschat, D.; Schumann, A.; Meinlschmidt, P.; Gunschera, J.; Salthammer, T.

doi: 10.1007/s12127-013-0141-5pmid: N/A

The purpose of the investigations reported was a feasibility study of field asymmetric ion mobility spectrometry (FAIMS) applications for the characterization of recovered wood. Especially the treatment with organic wood preservatives represented by their active substances should be detected in concentrations commonly used for timber products. The following pesticides were determined: PCP, lindane, dichlofluanide, tolylfluanide, propiconazole, tebuconazole, IPBC (iodine-propyl-butyl-carbamate), K-HDO ((N-Cyclohexyl-diazeniumdioxy)-potassium) and fenoxycarb. The first step was to show that such compounds can be vaporized under moderate conditions. Solid-phase microextraction (SPME) was capable for sampling and enrichment. The reference analytics was made by gas chromatography coupled with mass spectrometry (GC-MS). Both, waste wood, in this case window frames from reconstruction work, and self-prepared doped wood samples were utilized. For analyzing the complex mixture of vaporized native and artificial ingredients of the lignocellulose material a chromatographic pre-separation was necessary. Hence, the second step was to study the behavior of active substances in the analysis with GC-FAIMS to clarify which peaks in positive and negative mode are dedicated to wood preservatives. At least one strong signal from every selected active compound was located for clear identification. With that knowledge, FAIMS was successfully applied for the distinction of natural and treated wood samples. The discrimination can be a basis for industrial sorting plants which could help to increase the contemporary amount of material usage of recovered wood for a more ecological and economical handling of natural resources.

Han, Fenglei; Li, Haiyang

doi: 10.1007/s12127-013-0144-2pmid: N/A

Drift tube Ion Mobility Spectrometry (IMS) is an atmospheric analysis technology which was developed in the 1970s. It has been widely used in the detection of drugs, explosives and environmental monitoring. IMS has characteristics of high sensitivity, portability and quick detection. In addition, it has a focusing effect for the ions passed by. In the work reported in this paper, a variable DC electric fields Ion Mobility Spectrometry was constructed, and the characteristic of focusing was studied by simulation and experiments. The results showed that the focusing effect had a strong correlation with the field distribution. With the increasing of the additional voltage δv, the focusing effect enhanced. The peak intensity of the IMS increases, and the drift time increases firstly and then decreases. The good agreements between simulation and experiment show that the simulation has predictive power for ion motion in IMS. This study can serve as visual aids for intuitively understanding the factors that determine ion transport.

Valadbeigi, Younes; Tabrizchi, Mahmoud

doi: 10.1007/s12127-013-0142-4pmid: N/A

Sodium lauryl sulfate (SLS) and sodium lauryl ether sulfate (SLES) are commonly used in many dishwashing liquids. These chemicals are adsorbed on the dish surface during the washing process and then transferred to food or drink in the cooking process. In this work, the adsorption of SLS and SLES on different dish surfaces in aqueous solution was studied. Stainless steel, copper, aluminum, Pyrex, Teflon and arcopal china ware were used in this study. The adsorbed chemical remained on the surface after rinsing was measured by thermal desorption using an ion mobility spectrometer as the detector. Although arcopal china ware showed the maximum amount of adsorption, and Pyrex and stainless steel dishes showed the minimum amount of residual chemical, the results showed that the amount of adsorbed chemicals on dish surfaces is less than 428 ng.cm−2, which is well below the health risk dosage. The released SLS and SLES from dish surfaces into cold or hot water were also measured and compared for different dishes.

Roscioli, Kristyn; Lamabadusuriya, Manuja; Harden, Charles; Midey, Anthony; Wu, Ching; Siems, William; Hill, Herbert

doi: 10.1007/s12127-013-0143-3pmid: N/A

The overall objective of this project was to develop an analytical method that utilizes structure selective ion molecule interactions (SSIMI) in ion mobility spectrometry (IMS) to shift the mobility of a targeted analyte through the addition of a gas phase modifier to the buffer gas. IMS is a sensitive, rapid method for the detection of harmful chemicals; however false alarm responses do occur and a reduction in their frequency decrease both the cost and time required for detection. The investigation reported here probed the effects of a series of buffer gas modifiers on the mobilities of chemical warfare agent simulants (CWAs), toxic industrial chemicals (TICs) and a known interference (butyl carbitol) found in fire extinguishing agents. The major finding of this research was that a modifier with a proton affinity similar to, but not greater than, the target analyte produced the greatest changes in mobilities due to the formation of an ion cluster between the neutral modifier and target analyte ion. Mass spectrometry was utilized to confirm the formation of ion-neutral clusters that caused the target ion to shift its mobility. While a number of modifiers were screened, acetonitrile and isobutyronitrile were found to have sufficiently selective SSIMI with the target compound. For example, in the presence of acetonitrile modifier, the protonated response ion of the CWA simulant DMMP, [DMMP]H+, had a mobility shift of 10.8 %, but the mobility was unchanged for the interferent, butyl carbitol. The mobility of the simulant DMMP decreased with the introduction of modifiers, while the mobility of the interference did not change, demonstrating the potential of the SSIMI technique for reducing false alarm rates.