FTIR/MS Spectra

Abstract A new thiourea ligand, N-[l,10-phenanthroline]-N -[(benzo-15-crown-5)yl]thiourea has been synthesized from the reaction of 5-amino-1,10-phenanthro-line with 15-isothiocyanatobenzo[15-crown-5] and its Cu(I) complex has been prepared. The stmctures of the ligand and its complex have been characterized by elemental analysis, UV-vis, FTIR, H NMR (DMSO-dg), NMR (DMSO-dg) and MS spectra (LC-MS). 

If preliminary results indicate the presence of a Scheduled chemical, which is not in the spectral libraries, its structure elucidation is carried out. The GC/EI/MS, GC/CI/MS, and LC/MS spectra are interpreted. Molecular weight and presence of heteroatoms like sulfur, chlorine, and phosphorus is determined. GC/HRMS and LC/MS/MS assist in interpretation of the fragmentation of ions of interest. Elemental composition of the molecular and fragment ions can be determined with GC/HRMS. Interpretation of GC/FTIR spectrum provides information on functional groups (when reporting in a PT, note that IR spectrum interpretation is not considered sufficient for identification), and the different... 

Both Soderstrom et al. (25) and Creasy et al. (26) have applied GC/FTIR together with several other hyphenated chromatographic techniques to analyze CWC-related chemicals in complex matrices. The results of the different technique have been combined to unequivocally identify the relevant chemicals in low concentrations. In both studies, IR and MS spectra have been used together in spectral interpretation. Weimaster et al. (70) studied samples collected in Iraq, using a very wide variety of instrumentation, but they could not find any scheduled chemicals. 

Three new diastereomers of 3-hexyl-5-methylindolizidine, (5Z,9Z)-, (5E,9E)- and (5Z,9 ), Fig. (8), were identified in different collections of thief ants Solenopsis (Diplorhoptrum) species from Cahfomia. The identification of these alkaloids resulted from the analysis of their MS spectra and comparison of their GC-FTIR spectra. The authors also emphasised the chemotaxonomic value of the stereochemistry of these alkaloids [23]. 

Fig. 12.21 GC-FTIR-MS hybridization, (a) Scheme of the configuration, (b) Information available from linked accurate mass measurement (AMM) electron ionization (El)-chemical ionization (Cl) and infrared spectra. (Reproduced from [53] with permission of the American Chemical Society).

FTIR and MS spectra measured during the second decomposition step at 290°C (i.e. after 25 minutes) are shown in Figure 6.18. The FTIR spectrum contains the same absorptions as shown in Figure 6.16 (H20, C02 and HCN). In this spectrum, however, two weak absorptions at 2144/2166 cm-l are visible. The mass spectrum shows m/z values of C02 (m/z = 44), HCN (m/z =... 

Figure 1. (A) FTIR and (B) MS spectra of water, carbon monoxide and carbon dioxide.

After calibration by means of PulseTA it is possible to properly quantify the MS spectra not only for one evolved gas but also for multicomponent mixtures. This is illustrated by comparing the results obtained with both spectroscopic methods for the decomposition of zinc oxalate dihydrate (gaseous products water, CO and CO2). These results clearly show the advantages and drawbacks of both MS and FTIR for qualitative and quantitative analysis of the gas phase. Due to fragmentation of the evolved CO2 the results obtmned by TA-MS (Figure 8) can not be used for unambiguous confirmation of CO formation without calibration of the mass spectrometric signals. 

The evolved gas analyses were conducted on FTIR and mass spectroscopy (MS) devices, coupled to the TG apparatus. The main volatile compounds released below 350 °C were carbon dioxide and water vapours, which increased during the whole thermal decomposition process. Alcohol traces and aromatic structured compounds were also identified. Volatile structures containing carbonyl groups were found in the gaseous mixture at temperature values above 350 °C. Ammonia evolvement was also found in the gaseous mixture. The MS spectra were in good correlation with the findings from the FTIR spectra data. 

Comparing GC/FTIR and GC/MS, advantages and limitations of each technique become visible. The strength of IR lies—as discussed before—in distinguishing isomers, whereas identi cation of homologues can only be performed successfully by MS. The logical and most sophisticated way to overcome these limitations has been the development of a combined GC/FTIR/MS instrument, whereby simultaneously IR and mass spectra can be obtained. 

A series of 0-alkyl methylphosphonic acids were synthesized by reaction of methylphosphonic dichloride with appropriate alcohol. Obtained acids, after derivatization were examined using GC/MSD/FTIR Hewlett Packard system. Diazomethane methylation and BSTFA silylation were used to obtain derivatives convenient to GC process. Van den Doole retention indices against M-series, El and ammonia Cl MS spectra as well as FTIR spectra were obtained and discussed in the paper. 

The hyphenated techniques CGC - MS. CGC -FTIR, and CGC-AED are generally used as stand-alone units. Due to the nondestructive character of FTIR, CGC-FTIR-MS units (Fig. 39) are possible and have been commercialized. The software then allows simultaneous recording of the infrared and mass spectra of the eluting compounds. In principle. CGC-FTIR-MS-AED is also jxrssible if an open split interface is applied for the CGC- FTIR-MS combination and the split-line is directed into the AED detector. The fundamental aspects of CGC-MS, CGC-FTIR and CGC-AED are discussed in [58], [59], and [60]. 

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