The use of collisional-activation dissociation (CAD) in the electrospray transport region was evaluated for generating structural information on several pesticides and antibiotics. The collision energy used to generate the CAD spectra could be varied easily by changing the capillary/skimmer potential difference, imparting from 0 eV to above 16 eV internal energy to the near thermal ions generated by electrospray. The internal energy distribution for low-energy collisions (capillary/skimmer potential difference of 20 V) closely matches the curves generated by a triple-quadrupole mass spectrometer. Furthermore, the CAD spectra for selected compounds generated by electrospray in the transport region at a capillary/skimmer potential difference of 30-50 V closely resembled those obtained from the [M + H]+ ion by a triple quadrupole using 30 eV collision energy. The CAD of ions in the transport region resulted in 70% to 80% daughter-ion yields and minimal loss in overall ion current compared to the ion current for protonated or cationized parent molecules. The major daughter ions for 10 pg of Aldicarb and penicillin G could be detected (signal-to-noise ratio greater than 5) under full-scan CAD conditions.

The versatility and resolving power of countercurrent chromatography (CCC) has been demonstrated with a newly developed analytical high-speed planet centrifuge system. Interfacing countercurrent chromatography with mass spectrometry (MS) provides a new analytical methodology that integrates the advantages of countercurrent chromatography with the low detection limit and identification capability of mass spectrometry. In this paper the capability of thermospray CCC/MS is demonstrated in identifying and validating the bioactive and structurally known lignans from a crude extract of Schisandra rubriflora Rhed et Wils, a traditional Chinese herbal medicine for treatment of hepatitis.

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Like most dyes, Basic Yellow 2 (BY-2) fades upon prolonged exposure to light. Light-induced fading is a complex process that is also affected by beat and humidity. In order to better understand the photodegradation process and to identify the various photodegradation products of BY-2, fabric samples and solutions containing BY-2 were exposed to a variety of fading conditions. The analysis of faded BY-2 dyed fabric extracts by high-performance liquid chromatography/mass spectrometry (HPLC/MS) indicated the reduction and hydrolysis of the C=NH,+ group to form primarily benzophenone derivatives, as well as various demethylated products. Due to the absence of fragmentation in the thermospray spectra (only IM + HI+ ions were observed) the dye extracts were analyzed by gas chromatography/mass spectrometry (GC/MS) to confirm the identity of the degradation products. Many of the degradation products were sufficiently volatile for analysis by GC/MS. Mass spectra of the photodegradation products of BY-2 exhibited molecular ions and structurally important fragment ions to complement the thermospray data. The mass spectral data indicated that the most prevalent degradation product formed was ((CH,),NC6H,),C=0 (Michler's ketone). Hydrolysis of the C=NH, + group to C-0 is the main color-destroying reaction in the fading of BY-2. Demethylation products which can alter the shades of color were also detected in the faded BY-2 samples.

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