Serial sample introduction

ESI and APCI techniques are limited by the rate of sample introduction into the ion source. Autosampler technology is the primary rate-determining factor but in addition to this, fluid transfer rates and chromatographic separation can also be bottlenecks in the process. TWo approaches, generally categorized as parallel sample introduction and fast serial sample introduction, have been taken to increase the throughput. 

The total extraction time for these samples was 12 minutes per extraction. However, the procedure was conducted twice for aged samples to ensure complete extraction of the desired materials. Therefore, the overall analysis time was 24 minutes per sample. This time estimate can be misleading. The design of our system is such that the extractions are conducted in a combination of serial and parallel fashion, reducing overall analysis time. Illustrated in Table I is the extraction program for Diuron from Tama soil. Prior to the start of this method program, modifier has been introduced to each extraction vessel in a stepwise fashion. This procedure is carried out to insure that there is no pressure build-up where modifier introduction... 

Ruzicka, the head of one of the pioneering teams In FIA, designed various assemblies for the preconcentration of traces of metal Ions prior to their determination by atomic absorption or ICP spectroscopy in a variety of liquid matrices by use of small columns (5 mm x 2 mm I.D.) packed with the chelating resin Chelex-100 (50-100 mesh). The most Interesting of such assemblies [22] are shown in Fig. 4.14. The first assembly (Fig. 4.14a), the simplest of all, features a single line with two serial Injection valves (Ii for insertion of sample and Ij for Introduction of the eluent) prior to the column on which the analytes are retained. First the sea water sample is Injected and driven to... 

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