Stable room-temperature ionic liquids (RTILs) have been used as novel reaction solvents. They can solubilize complex polar molecules such as cyclodextrins and glycopeptides. Their wetting ability and viscosity allow them to be coated onto fused silica capillaries. Thus, 1-butyl-3-methylimidazolium hexafluorophosphate and the analogous chloride salt can be used as stationary phases for gas chromatography (GC). Using inverse GC, one can examine the nature of these ionic liquids via their interactions with a variety of compounds. The Rohrschneider-McReynolds constants were determined for both ionic liquids and a popular commercial polysiloxane stationary phase. Ionic liquid stationary phases seem to have a dual nature. They appear to act as a low-polarity stationary phase to nonpolar compounds. However, molecules with strong proton donor groups, in particular, are tenaciously retained. The nature of the anion can have a significant effect on both the solubilizing ability and the selectivity of ionic liquid stationary phases. It appears that the unusual properties of ionic liquids could make them beneficial in many areas of separation science.

Room-temperature ionic liquids are useful as solvents for organic synthesis, electrochemical studies, and separations. We wished to examine whether their high solubalizing power, negligible vapor pressure, and broad liquid temperature range are advantageous if they are used as matrixes for UV-MALDI. Several different ionic matrixes were synthesized and tested, using peptides, proteins, and poly(ethylene glycol) (PEG-2000). All ionic liquids tested have excellent solubilizing properties and vacuum stability compared to other commonly used liquid and solid matrixes. However, they varied widely in their ability to produce analyte gas-phase ions. Certain ionic matrixes, however, produce homogeneous solutions of greater vacuum stability, higher ion peak intensity, and equivalent or lower detection limits than currently used solid matrixes. Clearly, ionic liquids and their more amorphous solid analogues merit further investigation as MALDI matrixes.

The advent of high-efficiency microbial separations will have a profound effect on both chemistry and microbiology. For the first time, it appears that it may be possible to obtain qualitative and quantitative information on microbial systems with the accuracy, precision, speed, and throughput that currently is found for chemical systems. Recently it was suggested that an analytical separations-based approach for determining the viability of cells would be advantageous. The feasibility of such an approach is demonstrated using CE-LIF of two bacteria and yeast. The analytical procedures and figures of merit are outlined. High-throughput analyses and evaluation of microorganisms now appear to be possible.

The operation cost of an intelligent high-speed train system is greatly increased by the enormous energy demand of large-scale signal and sensor networks. However, the wind energy generated by high-speed trains is completely neglected. Herein, a wind-energy-harvesting device, which is based on an elastic rotation triboelectric nanogenerator (ER-TENG), is fabricated to harvest the wind energy generated by high-speed moving trains and power the relevant signal and sensing devices. Due to the significant decrease in friction force resulting from reasonable material selection and elastic structure design, the energy-harvesting efficiency of an ER-TENG is doubled and the durability is increased by 4 times compared to the same characteristics of a conventional rotation sliding triboelectric nanogenerator (RS-TENG). Our findings not only provide an in situ energy-harvesting pattern for an intelligent high-speed rail system by recovering the otherwise wasted wind energy generated by high-speed trains but also offer a potential strategy for large-scale wind energy harvesting by TENGs.

Gas ch romatog ra phy Chiral separation Methylated cyclodextrin Room temperature ionic liquids 1-bulyl-3-methyhmidazohu m chloride SummaryRoom temperature ionic liquids (RTIL) are molten saJtswith melting points well below room temperature. 1-bulyl-3-methyhmidazohum chloride is a lypical example of such RTIL. Itwas used as a solvent to dissolve permethylated-13-cyclodextrin (BPM) and dimethylated-[Scyclodextrin (BDM) to prepare stationary phases for capillary columns in gas chromatography for chiral separation. The RTIL containing columns were compared to commercial columns containing the same chiral selectors. A set of 64 chiral compounds separated by the commercial BPM column was tested on the RTIL BPM column. Only 21 were enantioresolved. Similarly, a set of 80 compounds separated by the commercial BDM column was passed on the RTIL BDM column with only 16 positive separations. It is proposed that the imidazohum ion pair could make an inclusion complex with the cyclodextrin cavil,/, blocking it for chiral recognition. All the chiral compounds recognized by the RTIL columns had their asymmetric carbon that was part of a ring structure. The retention factors of the derivatized solutes were lower on the RTIL columns than those obtained on the commercial equivalent column. The peak efficiencies obtained with the RTIL capillary were significantly higher than that obtained with the commercial column. These observations may contribute to the knowledge of the mechanism of cyclodextrin-based GC enantioselective separations.