MS spectral data

Computerised identification of polymer additives on the basis of MS spectral data has been reported [1]. 

Fully unsaturated group 14 2-trimethylsilyl-l-heteropines 36 and C-unsubstituted parent rings 37 were obtained from the common starting compound (Z)-l-(bromophenyl)-4-trimethylsilyl-l-butyn-3-ene 35, as shown in Scheme 4 <1999CPB1108>. Structures of the newly prepared compounds 36 and 37 were confirmed by H NMR and MS spectral data. 

Table 3.15 ESI/MS spectral data of pigments isolated in fraction iv) (scheme of Figure 3.19) from Shiraz grape marc extract and wine, nd not detected. Analytical conditions ion source and orifice potentials 5.5 kV and 30 V respectively, positive ion mode. Curtain gas N2 8 units nebulizer gas air 10 units injected solution 50% acetonitrile acidified with 2.5% acetic acid (rate 5p,L/min) (Asenstorfer et al., 2001).

Table I, shows the spectrometers recently developed by the authors. All are based on the principle of multichannel spectroscopy utilizing image devices as sensors (1). In these spectrometers, a spectrum is scanned rapidly electronically, typically in 10 ms. Spectral data can be readily available ina digitized form, the sensitivity of these image devices is generally better than...

A similar peroxide shunt route from a coordinatively saturated di-iron(III) complex [Fe2(/u-0)-(/.t-OAc)2(HEXPY)] +(37a) " (HEXPY=l,2-bis[2-bis(2-pyiidylmethyl)-6-pyridyl]ethane) resulted in the (peroxo)di-iron(lll) species (37b) (Table 2), which is stable at room temperature in the solid state. Elemental analysis and FAB-MS spectral data obtained for a dark purple species generated by treating (37a) with Fl202/Et3N at —30 °C match those expected for [Fe2(02)(0)(0Ac)-(HEXPY)](0Tf)-5H20. 

Structure of the transformation product PTP-207B. As the weakest bond in this molecule was thought to be the nitrogen-carbon bond of the carbamate, the formation of m/z 134 was favored over other fragmentation routes. This resulted in a rather simple fragmentation pattern of PTP-207B in the positive ion mode. The other two transformation products were also identified with the comparison of MS spectral data (data not shown). As to the analytical approach employed, the use of LC-QqLIT-MS and UPLC-QqToF-MS proved to be a powerful combination for elucidating the imknown structures of the phototransformation products [18]. 

Compound 1 was obtained as white powder. The molecular formula was determined as C41H66O12 by C NMR DEPT spectrum and FAB MS spectral data(m/z 773 [M+Na]. The IR spectrum indicated the presence of hydroxyl ( VmK 3400, 1070cm ) and carboxylic ester(v,Mx 1733cm ) groups. Acid hydrolysis of 1 yielded L-rhamnose and D-glucose identified by PC comparison with authentic samples. 

Silva and Lopes analyzed solutions of iodobenzene dicarboxylates in acetonitrile, acetic acid, aqueous methanol and anhydrous methanol by electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS) [196]. The major species found in the solutions of PhI(OAc)2 in acetonitrile, acetic acid and aqueous methanol were [PhI(OAc)2Na]+, [PhI(OAc)2K]+, [Phl]+, [PhIOAc]+, [PhIOH]+, [PhI02Ac]+, [PhI02H]+ and the dimer [Ph2l202Ac]+. On the other hand, the anhydrous methanol solutions showed [PhIOMe]+ as the most abundant species. In contrast to the data obtained for PhI(OAc)2, the ESI-MS spectral data of PhI(02CCF3)2 in acetonitrile suggests that the main species in solutions is iodosylbenzene [196]. A similar ESI-MS and ESI-MS/MS study of solutions of [hydroxy(tosyloxy)iodo]benzene has been performed under different conditions and, based on these data, mechanisms were proposed for the disproportionation of the iodine(III) compounds into iodine(V) and iodine(I) species [197]. 

TABLE I-GC2/ND RETENTION TIME DATA AND GC2/MS SPECTRAL DATA USED FOR IDENTIFICATION OF NITRO-PAH IN A DIESEL PARTICULATE EXTRACTa... 

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