AutoAnalyzer sampler

The instrumentation used is part of the AutoAnalyzer system manufactured by Technicon, Inc. 19), The AutoAnalyzer modules required are the sampler, the proportioning pump, the colorimeter with range expander, and the recorder. The AutoAnalyzer sampler alternately delivers sample solution and cleansing water from a small reservoir. The quantity of sample is controlled by the sampling rate, adjusted by means of a cam on a clock mechanism, and by the diameter of the sample tube on the manifold of the pump. 

Even complex procedures can be automated, such as dialysis to clean up dirty samplers, solvent extraction, automatic distillation and on-hne UV digestion. Unhke the earlier AutoAnalyzer systems which use a purely step-wise autosampler, the TRAACS is fitted with a random-access sampler as standard. 

WA water quality labs by atomic absorption and autoanalyzer techniques. Charge balance calculations Indicated that all dissolved species of significance were analyzed. Comparison of filtered and unflltered aliquots suggested that un-lonlzed species were not present In appreciable quantities. Sampling and analysis uncertainties were determined by the operation of two co-located samplers for 16 weeks. The calcium and sulfate data were corrected for the Influence of sea salt to aid In the separation of the factors. This correction was calculated from bulk sea water composition and the chloride concentration In rainwater (11). Non seasalt sulfate and calcium are termed "excess" and flagged by a ... 

Method. A diagram of the apparatus is shown in Fig.4.29. Any suitable liquid chromatograph may be used. The AutoAnalyzer is modified such that the liquid sampler is fitted to the end of the chromatographic column. The proportioning pump is by-passed. The set-up of the AutoAnalyzer is the same as that for normal measurements of cholinesterase. The application of this technique to the determination of CGA 18809 in plum-leaf extract is shown in Fig.4.30. A comparison is made with UV analysis of the same extract. The limit of detection for CGA 18809 is c . 20 ng at a 3 1 signal to noise ratio. The relative inhibitions of several organophosphates and carbamates are compared in Table 4.9. Diazoxon may be detected in low picogram quantities. 

The data presented are for samples collected by using a pump-profiling system designed to minimize atmospheric contamination. This pump sampler was attached at the end of a 400-m electrical cable with a conductivity, temperature, and depth device (CTD, Seabird SBE-9/11). The nylon hose was interfaced to an autoanalyzer for detailed analyses of N03 , N02 , NH4+, H4Si04, PO,3, and H2S. Discrete samples were taken for oxygen, manganese, and iron. 

Fio. 10. AutoAnalyzer recorder tracings illustrating interaction between samples when urea solutions of the concentrations indicated (mg/100 ml) are analyzed sequentially at a sampling rate of 40/hour. When a Sampler Type I is used (I) interaction is eliminated by a water wash between samples (right), but with a reduction to half the effective rate of sampling. The Sampler II, which incorporates a water wash in its functioning, virtually eliminates interaction without a reduction in sampling rate (II). 

Type 3. The Implementation of all the preliminary operations in the analytical process without human Intervention represents a remarkable degree of automation. By Incorporating a sampler In ordinary FIA assemblies or the classical AutoAnalyzers, the first stage of the analytical process could be regarded as automated. However, It should be noted that the sampler holds pre-treated samples, so that the automation of the first stage Is only apparently complete. 

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