Continuous online process analytics with multiplexing gas chromatography by using calibrated convolution matrices.

The development of fast and precise measurement techniques for process analytical technology is important to operate chemical processes safely and efficiently. For quantitative measurements of multiple components at a trace level, often gas chromatographic methods are used which have a response time of several minutes or of up to one hour. For fast changing processes, this can be too slow for efficient control.

Online High Throughput Measurements for Fast Catalytic Reactions Using Time-Division Multiplexing Gas Chromatography.

Developing new catalysts is crucial for optimization of chemical processes. Thus, advanced analytical methods are required to determine the catalytic performance of new catalysts accurately. Usually, gas chromatographic methods are employed to analyze quantitatively the product distribution of volatile compounds generated by a specific catalyst.

Online Continuous Trace Process Analytics Using Multiplexing Gas Chromatography.

The analysis of impurities at a trace level in chemical products, nutrition additives, and drugs is highly important to guarantee safe products suitable for consumption. However, trace analysis in the presence of a dominating component can be a challenging task because of noncompatible linear detection ranges or strong signal overlap that suppresses the signal of interest. Here, we developed a technique for quantitative analysis using multiplexing gas chromatography (mpGC) for continuous and completely automated process trace analytics exemplified for the analysis of a CO stream in a production plant for detection of benzene, toluene, ethylbenzene, and the three structural isomers of xylene (BTEX) in the concentration range of 0-10 ppb.

Microsolvation of molecules in superfluid helium nanodroplets revealed by means of electronic spectroscopy.

The empirical model explaining microsolvation of molecules in superfluid helium droplets proposes a non-superfluid helium solvation layer enclosing the dopant molecule. This model warrants an empirical explanation of any helium induced substructure resolved for electronic transitions of molecules in helium droplets. Despite a wealth of such experimental data, quantitative modeling of spectra is still in its infancy.

Rotational spectroscopy of single carbonyl sulfide molecules embedded in superfluid helium nanodroplets.

The pure rotation spectrum of carbonyl sulfide embedded in superfluid helium nanodroplets was measured in the frequency range from 4 to 15.5 GHz. Four lines, corresponding to the J = 1-0, J = 2-1, J = 3-2, and J = 4-3 transitions, were found.

Evidence for an energy level substructure of molecular states in helium droplets.

The pure tunneling inversion transition of ammonia embedded in (4)He droplets was investigated in the microwave frequency range. We observed a spectrum that consists of a sharp peak, only 15 MHz wide, on top of a broad feature. The peculiar line shape could be simulated with an empirical model and is a clear experimental evidence for an energy level substructure of molecular states in doped helium droplets.

Structure and dynamics of phthalocyanine-argonn (n = 1-4) complexes studied in helium nanodroplets.

Van der Waals clusters of phthalocyanine with 1-4 argon atoms formed inside superfluid helium nanodroplets have been investigated by recording fluorescence excitation spectra as well as emission spectra. The excitation spectra feature a multitude of sharp lines when recorded in superfluid helium droplets in contrast to the respective spectra measured in a seeded supersonic beam (Cho et al. Chem.

Fine structure of the (S(1)<--S(0)) band origins of phthalocyanine molecules in helium droplets.

The laser-induced fluorescence (LIF) excitation spectra of free base phthalocyanine (Pc), Mg-Pc, and Zn-Pc molecules in superfluid helium droplets at T=0.38 K have been studied. The spectra reveal the rich vibronic structure of the S(1)<--S(0) electronic transitions.

Microsolvation of phthalocyanines in superfluid helium droplets.

Experimental and theoretical investigations of the spectroscopy of molecules in superfluid helium droplets provide evidence for the key role of the first helium layer surrounding the dopant molecule in determining the molecule's spectroscopic features. Recent investigations of emission spectra of phthalocyanine in helium droplets revealed a doubling of all transitions. Herein, we present the emission spectra of Mg-phthalocyanine and of phthalocyanine-argon clusters in helium droplets, which confirm the splitting as a general effect of the helium environment.