Hamilton microsyringe

The trough itself measured 20 x 12 cm, was milled from a block of Teflon, and held approximately 750 ml of liquid. Monomolecular films were prepared on a subphase of (ultrapure) distilled water or on aqueous subsolutions containing varying concentrations of either NaF, HC1, NaOH, thiourea, or dimethyl sulfoxide (DMSO). Aliquots, between 50 and 250 pi, of the ethanol-solubilized microbubble-surfactant mixture were applied slowly to the surface of the subsolution from a Hamilton microsyringe. It was found unnecessary to allow the films to stand for more than 2 min after spreading before taking measurements. Furthermore, following compression or expansion, the surface pressure was observed to remain constant for periods of up to at least 10 min. All measurements were made at 20.0 0.5°C. 

With the CD phases saturated vapours of the test substances were injected with a Hamilton microsyringe. 

Precision in the delivery of the sample volume is of m or importance. Hamilton microsyringes are often used instead of automatic dispensing pipets. 

Ten-microliter volumes are syringe loaded using a MC-50 micropipette tip attached to a Gilson micropipettor. Fifty-microliter volumes are syringe loaded using a Hamilton microsyringe. 

Samples were injected onto the head of the column through a silicone rubber diaphragm by means of a 1 yl Hamilton microsyringe with standard needle. Frequent replacement of the diaphragm rubber was found to be necessary due to the high temperature used for vaporisation of the organotins, and the high pressure differential across the column itself. The speed of injection was not found to... 

Hamilton microsyringes or pipettes pulled from borosilicate glass capillaries. 

Injection vial crimps, 11-nrni, Teflon/silicone/Teflon, Sun Brokers Microsyringes, (25-, 50-, 100-, 250-, 500-pL), Hamilton Mill, Hobart... 

Injection port insert, cyclo-double gooseneck, Restek Magnetic stirrers, VWR, Model 200 Microsyringes, Hamilton Mill, Hobart Mill, Wiley... 

Samples consisting of 20—40 pL of an approximately 10% solution (depending on the degree of unsaturation) were injected through the septum using a 25 or 50 pL microsyringe fitted with a KelF adaptor (Hamilton Co. P. O. Box 10030, Reno, Nevada 89510, USA). 

FIGURE 27-3 A set of microsyringes lor ssrnple injection. (Courtesy Hamilton Company.)... 

Microsyringe with Chaney adapter (Hamilton Co.) for injection of liquid extracts 0.5 or 1.0 cm capacity gas-tight syringe for head-space sampling and direct injection (Precision Sampling Corp.)... 

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