Separator Ryhage

The nature of the separators is most important the LKB with the Ryhage separator and the Finnigan with a sily-lated glass jet separator gave appropriate sensitivity. 

The most common separators include the Ryhage or jet diffusion separator (74), the Watson-Biemann or pore diffusion separator (75), and the membrane solution diffusion separator originally developed by Llewellyn (75). The first two separators involve direct passage of the sample into the mass spectrometer the low molecular weight helium diffuses more readily and is pumped away. The membrane separator involves diffusion of the sample through a silicone membrane while the carrier gas vents to the atmosphere carrier gas is thus not confined to helium. There is no best separator the choice depends on the nature of the compounds, the temperature range over which it will be operated, and most usually what is available in a particular laboratory. A convenient configuration for a double-beam mass spectrometer such as the AEI MS-30 is two different separators, one into each beam, which permits rapid evaluation of separator performance. 

Figure 1.5. Molecular separators a) Two stage jet separator due to Ryhage Typical dimensions are d, = ds = KT cm, dj = 2.5 x 1(T cm, d4 = 3x 10 cm, I, = 1.5 x 10 cm, I2 = 5x (F cm. The first chamber is evacuated with a mechanical pump and the second by diffusion pump, b) Silicone membrane separator [26] in which the GC effluent is channelled in a spiral path in contact with the membrane surface, c) Watson-Biemann fritted glass...

In 1958, the first on-line GC-MS instruments were introduced. By means of the jet separator, introduced in 1964 by Ryhage [7], the practical aspects of coupling GC and MS were greatly simplified. A major breakthrough in GC-MS was realized in 1968 with the introduction of the first data-processing units [8]. In 1975, the first commercial GC-MS instruments with capillary columns were introduced. In 1981, fused-silica capillary columns were applied for GC-MS [9]. 

Ryhage, R. (1967), Efficiency of molecule separators used in gas chromatograph-mass spectrometer applications. Ark. Kem., 26,305. 

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