Technicon

Since 1970, new analytical techniques, eg, ion chromatography, have been developed, and others, eg, atomic absorption and emission, have been improved (1—5). Detection limits for many chemicals have been dramatically lowered. Many wet chemical methods have been automated and are controlled by microprocessors which allow greater data output in a shorter time. Perhaps the best known continuous-flow analy2er for water analysis is the Autoanaly2er system manufactured by Technicon Instmments Corp. (Tarrytown, N.Y.) (6). Isolation of samples is maintained by pumping air bubbles into the flow line. Recently, flow-injection analysis has also become popular, and a theoretical comparison of it with the segmented flow analy2er has been made (7—9). 

Fig. 1. Internal view of a clinical chemistry analy2et (Technicon RA-XT).

Separate sample blanking requires an additional analytical channel, and is therefore wasteflil of both reagents and hardware. An alternative approach that is used on several automated systems, eg, Du Pont ACA, BM-Hitachi 704, Technicon RA-1000, is that of bichromatic analysis (5) where absorbance measurements are taken at two, rather than one, wavelength. When the spectral curves for the interference material and the chromogen of the species measured differ sufficiently, this can be an effective technique for reducing blank contributions to assay error. Bichromatic analysis is effective for blanks of both the first and second type. 

It is estimated that the worldwide clinical chemistry diagnostics market is about 3 biUion. This amount includes an estimated 700 million in instmment sales, and 2.3 bUHon in sales of reagents and consumables. Some of the principal instmment manufacturers are Hitachi (Japan), Miles Laboratories/Technicon Instmments (United States), E. I. du Pont de Nemours (United States), Beckman Instmments (United States), Eastman Kodak (United States), Abbott Laboratories (United States), Olympus (Japan), Toshiba (Japan), Hoffmann-La Roche (Switzerland), and Ciba Corning Diagnostics (United States). 

In summation, the two-angle interval scattering method can provide CBC, RDW, PCT, and HDW. This two-angle interval method has been incorporated into the Technicon H 1 system which provides RBC, HCT, MCV, PLT, MPV, RDW, PDW, PCT, and HDW. 

The automated method differs from the ICSH method chiefly in that oxidation and ligation of heme iron occur after the hemes have been released from globin. Therefore, ferricyanide and cyanide need not diffuse into the hemoglobin and methemoglobin, respectively. Because diffusion is rate-limiting in this reaction sequence, the overall reaction time is reduced from approximately three minutes for the manual method to 3 —15 seconds for the automated method. Reaction sequences in the Coulter S + II and the Technicon H 1 and H 2 are similar. Moreover, similar reactions are used in the other Coulter systems and in the TOA and Unipath instmments. 

The polyamines putrescine, cadaverine, spermidine, and spermine, which are seen at elevated levels in some victims of cancer, were separated on a Technicon (The Technicon Company Chauncey, NY) TSM Amino Acid Analyzer packed with an 8% divinylbenzene-co-polystyrene sulfonated resin with post-column ninhydrin detection.111 Amines such as ethanolamine, noradrenaline, hexamethylene diamine, methoxytryptamine, spermine, and spermidine were separated from amino acids on a DC-4A cation exchange resin.112 A similar approach, using a Beckman Model 121M amino acid analyzer equipped with an AA-20 column, was also successful.113 A Polyamin-pak strong cation exchange column (JASCO) was eluted with a citrate buffer for the detection of putrescene, spermine, cadaverine, and 1,5-diaminohex-ane from rat thymus.114 A post-column o-phthaldehyde detection system was used. 

However, around 1983 Technicon introducted their "random access fluid technology, with retention nevertheless of the air segmentation, the whole being realized in the Technicon RA-1000 system. 

Fig. 5.20 shows the instrument with the addition of the ion-selective electrode (ISE) module, which performs Na, K and C02 analyses (240 samples or 720 tests per hour) as requested and without interruption of the other analyses. The sample for electrolyte determination is also placed on the sample tray and a third probe aspirates diluted sample from the reaction tray for processing by the ISE module. Finally, the Technicon SRA-2000 system is a computer-controlled network of the subsystems SMAC II and RA-1000. 

As a development of experience with the RA-1000 instrument, Technicon recently introduced their most advanced Chem 1 capsule chemistry system. It consists of a one-channel CFA with a capacity of 1800 tests per hour and provided with eight sequential optical detectors along its pathway, which... 

Technicon RA-1000, Technicon SRA 2000 and Technicon Random Access Fluid, leaflet 6603-R/3-84... 

Fig i.21 1SE channel of Technicon Chem 1 capsule chemistry system. 

Technicon Chem 1 system, 1985 The AutoAnalyst, Technicon Special Cardiff Edition, May 1985. 

Partial) dialysis in flow analysis. The sample solution flows along one side of the membrane, while the analyser solution passing (often in counter-current) on the other side takes up the diffused components from the sample. A dynamic equilibrium is reached (under steady-state conditions) in the leaving analyser solution, which is then analysed and from the result of which the analyte content can be derived via calibration with standard solutions treated in exactly the same way. This is a common procedure, e.g., in Technicon AutoAnalyzers, and has also been applied in haemoanalysis by Ammann et al.154 as described above. 

In many years of experience in the NIR applications department at Technicon Instruments, there was about an hour and a half available to teach both theory and practice of calibration to each group of new users the rest of the training time was spent teaching the students how to set the instrument up, prepare samples, take reproducible readings,... 

Flow injection analysis has been adapted to automatic air-segmented continuous flow systems, e.g., the Technicon AutoAnalyzer system. Several reducing... 

Bernard M, Macchi G, Automation in analytical chemistry, Technicon Symposia, Me-diad, New York (1965) 252... 

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