Glass fitting

A separation step is sometimes an essential part of an analytical method and may be as diverse as distillation, filtration, digestion, extraction, phase-separation or dialysis. These can all be performed by continuous flow analysers either by adding a specially designed glass fitting to the manifold or analytical cartridge or by the addition of a separate module to the analyser. Many biological samples contain protein and dialysis is often used to remove this protein, which would otherwise affect the analysis. 

The reaction flask should be connected to the receiver by a tube of large bore and equipped, preferably, with ground-glass fittings. Two traps between the receiver and the aspirator are desirable to assure no contact between the phosphorus chlorides and water. 

Still another O-ring joint design is based on a glass fitting with an inner thread4 (Fig 8.6). 

For best results the flask should have standard-taper, ground-glass fittings. 

In a 1-1. three-necked round-bottomed flask with ground-glass fittings is placed a mixture of 36 ml. of boron trifluoride etherate, 72 ml. of glacial acetic acid, and 120 ml. of chloroform (Note 1). The flask is equipped with a spiral reflux condenser, an efficient mechanical stirrer, and a dropping funnel (Note 2). The chloroform solution in the flask is heated and maintained at reflux with vigorous stirring, and a solution of 30 ml. of 1,3-propanedithiol (0.30 mole) and 29 ml. of methylal (0.33 mole) in 450 ml. of chloroform (Note I) is added at a constant rate... 

Figure 6.09. Ionic conductivity data for sodium potassium silicate glasses fitted to Hendrickson-Bray function (After Hendrickson and Bray, 1972).

Figure 7.10. (a) Conductivity data for Na20-Si02 glass fitted to the double-power law. (After Nowick et al., 1994) (b) Plot of the reduced conductivity vs the reduced frequency for the NFP glass (composition, Na3Fe2(P04)3) at various temperatures which could be fitted to double-power law (After Sobha and Rao, 1995). 

Then put all the said putrefied menstruum into a stdl of fine Venice glass, fit for the quantity thereof put on the limbeck, and close it to the stdl with a fine linen cloth dipped in the white of an egg, and then set it in Balneo Mariae, put to the receiver, which must be of great length, that the spirit respire not out again and with a very temperate heat separate the elements one from another, and then the element of air will issue forth first, which is an od. 

The main feature of the Carius tube test, which was developed by ICI as the so-called 10 g tube test, is the simplicity of its set-up (cf Figure 3-11) [21]. As the name already says, a 10 g sample is filled into a special Carius tube, which has a dip in the bottom to accommodate a thermocouple. The top may be closed using a metal/glass fitting, which contains a pressure sensor. The tube is placed into an oven, which may be heated up in a controlled linear way. In analogy to the DTA-set-up the temperature difference between sample and oven temperature s well as the pressme are reeorded. 

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