Automated batch analyzers

To avoid bottlenecks in the analysis, each step should be automated. Automation of data acquisition is achieved by automated HPLC/UV/MS/ ELSD instruments, equipped with autosamplers that allow compounds to be batch analyzed in unattended fashion. Recently, fast generic HPLC methods have been implemented for analysis of combinatorial libraries [33 53]. 

Ping L, Dasgupta PK. 1990. Determination of urinary mercury with an automated micro batch analyzer. Anal Chem 62(l) 85-88. 

The first attempts for automation of solution handling which made up the bulk of labour in an analytical laboratory was simply mechanizing and simulating the traditional batch operations under a conveyer-belt concept. This was an approach which proved to be cost effective and efficient enough to gain widespread acceptance. Batch analyzers which were more successful include the Dupont sample bag" analyzers and the parallel centrifugal analyzers. They are, however, expensive devices, and their use is rather limited, moreover, they are not designed to perform separations. 

Flow injection analysis (FIA) was developed in the mid-1970s as a highly efficient technique for the automated analyses of samples. °> Unlike the centrifugal analyzer described earlier in this chapter, in which samples are simultaneously analyzed in batches of limited size, FIA allows for the rapid, sequential analysis of an unlimited number of samples. FIA is one member of a class of techniques called continuous-flow analyzers, in which samples are introduced sequentially at regular intervals into a liquid carrier stream that transports the samples to the detector. ... 

Most dispensing systems are custom-made to meet the method of control or degree of automation required for the particular operation. Prior to installation of the dispenser, the system should be analyzed carefully to determine what possible batching errors could occur and, with the help of the admixture supplier, they should be eliminated. Commonly available dispensing systems and controls can be discussed under three main groups - fully automated, semi-automated or manual systems. 

In most instances, formulated drugs cannot be chromatographically analyzed without some preliminary sample preparation. This process can generally be categorized into sampling and sample cleanup steps with the overall goal of obtaining a representative subfraction of the batch. This chapter is a discussion of manual and automated sample preparation procedures for pharmaceutical formulations. 

Devices are now available for automated ordine extraction and sample preparation. These consist mainly of robotic arms and mechanisms for highly accurate and precise delivery of solvent volumes. Depending on the instrument, samples may be prepared and analyzed individually or in batches. 

Finally, contamination of sample spectra can also occur by cross-contamination during sample preparation and by carryover of residual analyte from a sample analyzed earlier in the run.172 173 Essentially, any component of the assay that is reused for each sample or batch of samples can be a source of cross-contamination or carryover. These include, for example, evaporators, pipettors, automated liquid handlers, recycled sample vials, and LC and GC autosamplers. Care needs to be taken in the selection of appropriate wash solvents that will readily solubilize the sample and analytes. This will usually be a combination of high percentage of organic solvents that may include a volatile acidic or basic modifier (e.g., formic acid or aqueous ammonia). Failure to properly wash all sample components from a chromatographic column can result in late eluting components appearing in the next, or later, analytical runs. 

Metabolite ID 1.4 operates in both interactive and batch mode. In the interactive mode, the user reviews the full-scan data prior to MS/MS generation. In batch mode, the user submits a list of samples to be analyzed and starts automated acquisition. With such automated approaches, the metabolic profile of a single compound can be evaluated in approximately 1.5 hours, provided that adequate separation can be achieved with short, narrow-bore columns and fast-gradient chromatography. 

CFA is very often used in process control. In CFA, the sampling process consists of samples flowing sequentially and continuously in a tube, where each sequentially mixes with reagents in the same tube at the same point downstream and then flows sequentially into a detector. Another automated device type is the discrete analyzer where the analysis is made by taking a batch sample at selected intervals and subjecting it to analysis. The main advantage of CFA is the objectivity assured by operator elimination at the sample pickup and sampling steps. However, when the complexity of the sample that is to be analyzed increases, CFA does not offer reliable analytical information therefore, one should use discrete analyzers as an alternative. 

Continuous-flow analysers in their segmented version prevailed in the automation of clinical chemistry for over a decade, until they began to be displaced by batch analysers which, oddly enough, where Introduced by the same manufacturers who launched and popularized SFA. This type of analyser was commented on In Chapter 5, which described in detail the Analyzers II, SMA 12/60 and SMAC, as well as a series of non-cllnlcal applications grouped according to the type of detection system used. 

Automatic instruments with discrete (batch) sample handling and analysis have special problems when used for automated process-control. These instruments consist of a sampling system, an analyzer, and a memory device that maintains the... 

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