Chromatograph automation

Complete chromatographic automation will bring planar chromatography to the same level as other chromatographic methods (33), like HPLC, giving to it an identical technological approach. Each step must be studied precisely in order to establish a schedule of conditions (34). 

SPME has been utilized for deterrnination of pollutants in aqueous solution by the adsorption of analyte onto stationary-phase coated fused-siUca fibers, followed by thermal desorption in the injection system of a capillary gas chromatograph (34). EuU automation can be achieved using an autosampler. Eiber coated with 7- and 100-p.m film thickness and a nitrogen—phosphoms flame thermionic detector were used to evaluate the adsorption and desorption of four j -triazines. The gc peaks resulting from desorption of fibers were shown to be comparable to those obtained using manual injection. 

J. A. Apffel, T. V. Alfredson and R. E. Majors, Automated on-line multi-dimensional high performance liquid chromatographic techniques for the clean-up and analysis of water-soluble samples , J. Chromatogr. 206 43-57 (1981). 

E. Menziani, B. Tosi, A. Bonora, P. Reschiglian and G. Eodi, Automated multiple development high-performance thin-layer chromatographic analysis of natural phenolic compounds , 7. Chromatogr. 511 396-401 (1990). 

Chlorophenoxy acids are relatively polar pesticides which are usually determined by LC because volatile derivatives have to be prepared for GC analysis. This group of herbicides can be detected by multiresidue methods combined with automated procedures for sample clean-up, although selectivity and sensitivity can be enhanced by coupled-column chromatographic techniques (52). The experimental conditions for Such analyses are shown in Table 13.1. 

One method that combines the good chromatographic properties with improved limit of detection is the separation of isoindole derivatives of amino acids that may be detected fluorimetrically. This method may be applied to protein hydrolysates, and used in automated format in routine analyses [22]. 

With the SMB system, solvents are recovered, continuously monitored, and analyzed by an automated software system. The chromatographic SMB process ensures that the solvents meet appropriate standards and cross-contamination is eliminated. 

Method development remains the most challenging aspect of chiral chromatographic analysis, and the need for rapid method development is particularly acute in the pharmaceutical industry. To complicate matters, even structurally similar compounds may not be resolved under the same chromatographic conditions, or even on the same CSP. Rapid column equilibration in SFC speeds the column screening process, and automated systems accommodating multiple CSPs and modifiers now permit unattended method optimization in SFC [36]. Because more compounds are likely to be resolved with a single set of parameters in SFC than in LC, the analyst stands a greater chance of success on the first try in SFC [37]. The increased resolution obtained in SFC may also reduce the number of columns that must be evaluated to achieve the desired separation. 

In addition to automated analysis, ISEs can be used to detect ionic species in chromatographic effluents. Particularly powerful is the coupling of modem ion... 

The reason for this lies not least in the increasing instrumentalization and delibei automation of all those processes which were earlier particularly subject to eri (Fig. 2). Modem high performance thin-layer chromatography (HPTLC) is no Ion inferior to other liquid chromatographic techniques with respect to precision and s sitivity (Fig. 3) [6]. 

Nokihara K, Gerhardt J Development of an improved automated gas-chromatographic chiral analysis system application to non-natural amino acids and natural protein hydrolysates. Chirality 2001 13 431. 

The catalyst testing was carried out in a gas phase downflow stainless steel tubular reactor with on-line gas analysis using a Model 5890 Hewlett-Packard gas chromatograph (GC) equipped with heated in-line automated Valeo sampling valves and a CP-sD 5 or CP-sil 13 capillary WCOT colunm. GC/MS analyses of condensable products, especially with respect to O-isotopic distribution, was also carried out using a CP-sil 13 capillary column. For analysis of chiral compounds, a Chirasil-CD capillary fused silica column was employed. 

Section I of this book includes chapters on the principles and practice of PLC. After this introductory Chapter 1, Chapter 2 provides information on efforts undertaken to date in order to establish the theoretical foundations of PLC. With growing availability and popularity of modem computer-aided densitometers, separation results can be obtained in digital form as a series of concentration profiles that can be relatively easily assessed and processed. From these, relevant conclusions can be drawn in exactly the same manner as in automated column chromatographic techniques. Efforts undertaken to build a theoretical foundation of PLC largely consist of adaptation of known strategies (with their validity confirmed in preparative column liquid chromatography) to the working conditions of PLC systems. 

Radke et al. [28] described an automated medium-pressure liquid chromatograph, now commonly called the Kohnen-Willsch instrument. At present, the method is widely used to isolate different fractions of soluble organic matter (for instance, as described in Reference 29 to Reference 31). A combination of normal phase and reversed-phase liquid chromatography has been used by Garrigues et al. [32] to discriminate between different aromatic ring systems and degrees of methylamine in order to characterize thermal maturity of organic matter. 

P.J. Dunlop, C.M. Bignell, J.F. Jackson, D.B. Hibbert, Chemometric analysis of gas chromatographic data of oils from Eucalyptus species. Chemom. Intell. Lab. Systems 30 (1995) 59-67. K. Varmuza, F. Stangl, H. Lohninger and W. Werther, Automatic recognition of substance classes from data obtained by gas chromatography, mass spectrometry. Lab. Automation Inf. Manage., 31 (1996) 221-224. 

The OPMBS used a custom-written spreadsheet application, i.e., a workbook, in conjunction with laboratory automation systems to standardize data recording, calculations, and presentation of results. Devising this approach required careful differentiation between (a) the workbook used to calculate and report the results and (b) the data acquisition systems used in each laboratory. The laboratory systems were used to collect the raw chromatographic data, but the calculation modules in the laboratory systems were not used. Instead, all calculations were done in the workbook. Use of the laboratory systems to collate and output the final results was considered but was rejected for two reasons. First, different laboratories used different systems, and some laboratories used more than one system. The output characteristics of the various systems differed considerably and would have required extensive modification... 

High-performance liquid chromatographic system equipped with an automated column switching system... 

The full-scan mode is needed to achieve completely the full potential of fast GC/MS. Software programs, such as the automated mass deconvolution and identification system (AMDIS), have been developed to utilize the orthogonal nature of GC and MS separations to provide automatically chromatographic peaks with background-subtracted mass spectra despite an incomplete separation of a complex mixture. Such programs in combination with fast MS data acquisition rates have led to very fast GC/MS analyses. 

Today, much more than just data are produced electronically. Many documents needed for studies that fall under the Good Laboratory Practice (GLP) standards regulations are being managed electronically. These records include not only data, such as chromatographic data from automated electronic capture systems and raw data collected in electronic field notebooks, but also other documents, such as methods, protocols, reports and standard operating procedures (SOPs). Frequently, these records are generated, distributed, reviewed, and archived electronically. 

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