Biologic injectors

The injector temperature should be determined by the nature of the sample and the volume injected, not by the column temperature. When analyzing biological or high-boiling samples, clean the injector body with methanol or other suitable solvent once per week. Install a clean packed injector liner and a new septum, preferably near the end of a workday. Program the column to its maximum temperature, then cool the column and run a test mixture to check the system using standard conditions. 

Orthophthalaldehyde (OPA) in combination with a thiol is the reagent of choice for derivatization, despite its inability to react with proline, hydroxyproline, and the sulfur-containing amino acids. Another drawback of the reagent is the instability of the reaction products, making an automated derivatization system coupled to an automated injector, and constant retention times an absolute necessity. Taking into account these considerations, the HPLC analysis will be of use to every biochemical genetics laboratory for biological fluids other than urine. The system has also a... 

A novel biologic administered using a 510(k) cleared pen injector... 

SE-30 (5 %) and Carbowax 20 m (1 %) as stationary phases on Chromosorb 60-80 mesh, acid washed. A solid injector was employed to prevent contamination of the column by non-volatile compounds present in the extracts of the biological material investigated. Satisfactory separation of the tropane alkaloids mentioned was obtained at temperatures above 210°C on the SE-30 column. 

Only the injectors of Bayer AG, Leverkusen, Germany have been investigated in this framework. They form the basis of Bayer s Tower biology for the aerobic waste water treatment of highly polluted industrial effluents. The two-component nozzles concerned are Bayer injector 8/14 and Bayer slot injector [626, 627), see Fig. 4.43, which are briefly discussed below. 

If the injectors are utilized for supplying activated sludge with aerial oxygen in a biological waste water purification plant, it is of particularly interest that they... 

Zinc Biological materials Polyurethane foam UV-Vis 5—20 ng mL1 Flow injection system mini-column at the injector port [217]... 

Splitless injection uses a similar injector design to split injection but is more suitable for quantitative analysis of trace components in dirty samples, such as biological and environmental extracts [41,49-59]. Conversion of a split to a splitless injector usually requires no more than the installation of a different liner and the interruption of the split flow at the start of the injection using a solenoid valve located in the vent line. The split flow is restarted only at the end of the sampling period. Since the flow of gas through the vaporization chamber is normally the same as the optimum carrier gas flow for the column the transport of sample vapors to the column is relatively slow. During the initial rapid evaporation of the sample there is minimal transfer of vapors into the... 

Ion chromatography (IC) has cemented its position as an integral part of analytical chemistty for the analysis of inorganic and biological ion analysis. IC operates on a principle similar to that of HPLC (a pump, injector, colmnn, and detector), but the main difference is that the entire flow path is constructed with a metal-free material. The principle... 

A practical difficulty in GC is that the nonvolatile fraction of any sample (common in biological matrices) remains precipitated on the wall of the injector or in the beginning of the column. These may accumulate, decompose, and may even catalyze decomposition of analytes, deteriorating the performance of the analysis. To avoid these problems, the injector needs to be cleaned frequently, and the front end of the capillary column (0.5 m or so) needs to be cut off occasionally and discarded. 

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