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Use of MS Detection

Current trends in GC relate to miniaturisation, fast-GC, improved selectivity (mainly for short columns), stability of column stationary phases (reduction of bleeding) and increasing use of MS detection [117]. Finally, GC can be readily hyphenated with spectroscopic techniques without using involved interfaces and thus can easily provide unambiguous solute identification. [Pg.195]

The use of MS detection has been demonstrated to be an indispensable tool in the analysis of complicated matrices because it can overcome the large number of interfering substances. [Pg.116]

Emphasis was placed on the extensive use of MS detection as the primary method for assessing the structure of unknowns generated during development. Comprehensive structure elucidation may require not only MS but also MS/MS or MS techniques coupled with NMR. The general principles of LC/MS and variations between instrumentation have been discussed in detail... [Pg.357]

The use of MS detection in electron ionization (El) mode increases selectivity with respect to ECD and enhances analyte identification potential conjointly with the GC retention time information. It can be used either in the full scan mode (observation of the full mass range) from which specific ions can be extracted, or in the SIM mode (observation of a few selected ions). [Pg.698]

Characterization of (recombinant) proteins at the molecular level requires the use of MS detection. [Pg.601]

This chapter discussed a number of sample preparation techniques that can be coupled on-line to GC. Special attention was devoted to SPE-GG as the prepara tion-plus-separation procedure, to the analysis of aqueous samples, and to analyte identification, i.e., to the use of MS detection. [Pg.191]

As in HPLC, the coupling of MS detection with CE has provided an excellent opportunity for more selective analysis, but the much reduced flow rates, small injection volumes, limitations in the types of buffers used [since electrospray ionization (ESI) is used in capillary electrophoresis/mass spectrometry (CE/MS)], and need to... [Pg.781]

Note that the interfacing of LC techniques with MS puts significant constraints on the solvents that can be used i.e., they must be volatile, with a low salt concentration, for MS compatibility. Narrow-bore columns, which use much smaller amounts of salt and organic modifier, appear to have potential for facilitating IEC-MS applications.40 Despite the excellent sensitivity of MS detection for most elements, however, there are cases where matrix effects can interfere. In this situation, combination of IEC with atomic emission spectrometry (AES) or atomic absorption spectrometry (AAS) may be preferable, and can also provide better precision.21 32 4142 Other types of... [Pg.288]

A recent extension of the scope of SPE-GC and SPE-GC-MS concerns the use of AED detection with its multielement detection capability and unusually high selectivity. Hankemeier [67] has described on-line SPE-GC-AED with an on-column interface to transfer 100 iL of desorbing solvent to the GC. The fully on-line set-up is characterised by detection limits of 5-20 ngL because of quantitative transfer of the analytes from the SPE to the GC module. On-line coupling of SPE with GC is more delicate than SPE-LC, because of the inherent incompatibility between the aqueous part of the SPE step and the dry part of the GC system. [Pg.437]

Compared with other LC detection modes (UV, MS), the use of IR detection in LC is still rather limited. [Pg.496]

For a 75 /.mi ID nano LC column as an example, the MS detection enhancement factor (ion count) in comparison to a 4.6 mm column is much higher than (4.6/0.075)2 = 3761 because of the reduction in sample molecular zone dilution and because a nano LC solvent flow rate at 0.02 to 2 /iL/min can be 100% directly sprayed into the MS ion source. No post-column flow splitting is required for nano-LC-MS as that required when 1 mL/min is used in a 4.6 mm ID column. This large enhancement of MS detection and the ability to directly interface with MS presents nano LC-MS as the best tool for life science research. [Pg.360]

Solubility screens using LC/MS detection do not require an ultra-pure sample of the test compound due to the selective detection of the mass spectrometer. Mass spectrometric detection offers high selectivity and low detection limits, which eliminates the need to develop complex chromatographic methods. The LC/MS-based solubility screen surpasses the traditional HPLC/UV-based equilibrium solubility assay with increased throughput, minimal manual intervention, and high sensitivity and selectivity. [Pg.418]

In the present review, we focus on the use of MS for the detection of both chemical and biochemical characteristics of bioactive compounds present in complex mixtures. The biochemical assays on which these methodologies are based rely on the direct or indirect detection of binding interactions by MS. [Pg.186]

Schwarz et al. used ESI-MS detection to characterize the composition of binary (bile salt/phosphatidylcholine) and ternary (bile salt/phophatidy 1-choline/fatty acid) mixed micelles that were used in micellar affinity capillary electrophoresis (43,44). The detrimental effects of the surfactants turned out to be tolerable for short-time qualitative determinations. [Pg.353]

NPH HCl) with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC HCl) as a coupling agent [593,594], The advantage is that with hydrazines it is possible to carry out the derivatization in milder conditions. An efficient postcolumn derivatization is obtained using avidin or streptavidin. In fact, these two proteins react in a very specific way with biotin, therefore they are bound with a fluorescent marker, such as fluorescein 5-isothiocyanate (FITC) to obtain fluorescent derivatives. Some authors [595] report the use of MS or MS/MS for biotin detection, but this method seems to be less sensitive than FLD. [Pg.626]

A large number of methods have been developed for analysis of water-soluble vitamins simultaneously in pharmaceutical products (like multivitamin tablet supplements). In fact, for these products no particular sample preparations are required and the high concentrations simplify the detection, enabling the use of UV [636]. The use of MS is also reported [637]. As well, Moreno and Salvado [638] reports also the use of a unique SPE cartridge (C18) for separating fat-soluble and water-soluble vitamins, which are, then analyzed using different chromatographic systems. [Pg.637]

In the human biological system, rocuronium bromide is eliminated unchanged by the biliary and urinary routes [15], and has two metabolites as mentioned in Section 4. As detailed in Table 6.2, determination of rocuronium bromide in biological samples was mostly carried out using LC-MS detection [16-23], although some workers made use of electrochemical detector [24—26] and only one report used a fluorimetric detector [27]. [Pg.293]

GC or, later, LC is employed both to separate the triazines and their metabolites from other compounds and to detect and quantify their presence. GC equipped with nitrogen-phosphorus (NPD) or electron-capture detectors still find use, but cost reductions in instruments for mass spectrometry (MS) have greatly increased the use of MS in routine analysis. MS provides confirmatory evidence of the identity of the compound. Different configurations of MS instruments allow the analyst to detect smaller quantities than previously possible. Detection limits are now several orders of magnitude lower than when the triazine herbicides were first introduced. [Pg.243]


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Detection using

MS Detection

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