Improvement in handling small liquid samples during sodium fusions
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Improvement in Handling Small Liquid Samples during Sodium Fusions In order t o perform a sodium fusion successfully on a liquid, most organic laboratory manuals recommend that the student drop his sample directly inta the cloud of bluish sodium vapor with- out striking the walls of the test tube, a procedure that requires good timing, a steady hand, and even a bit of luck. The odds for success can be significantly improved by theuseof a.small U-tube prepared from a 30-mm length of capillary tubing (0.3-0.5 mm ID) by heating its midpoint in a small yellow flame. The U-tube, depending on its diameter and how completely filled, will hold from 1 to 6 mg of liquid sample. After taking up the sample by capillary action, the U-tube can be placed in the fusion tube dong with the sodium, forced directly into the sodium with the open ends, or lowered into the hot sodium vapor from a stiff wire having a small loop at one end. In all csses the open ends of the U-tube should project downward so that the sample will be ejected inta the sodium as heating expands and volatilizes the liquid. THOMAS MCCULLOUGH, CSC Volume 49, Number 7 7, November 7972 / 771
Transcript of Improvement in handling small liquid samples during sodium fusions
Improvement in Handling Small Liquid Samples during Sodium Fusions
In order to perform a sodium fusion successfully on a liquid, most organic laboratory manuals recommend that the student drop his sample directly inta the cloud of bluish sodium vapor with- out striking the walls of the test tube, a procedure that requires good timing, a steady hand, and even a bit of luck. The odds for success can be significantly improved by theuseof a.small U-tube prepared from a 30-mm length of capillary tubing (0.3-0.5 mm ID) by heating its midpoint in a small yellow flame. The U-tube, depending on its diameter and how completely filled, will hold from 1 to 6 mg of liquid sample. After taking up the sample by capillary action, the U-tube can be placed in the fusion tube dong with the sodium, forced directly into the sodium with the open ends, or lowered into the hot sodium vapor from a stiff wire having a small loop a t one end. I n all csses the open ends of the U-tube should project downward so that the sample will be ejected inta the sodium as heating expands and volatilizes the liquid.
THOMAS MCCULLOUGH, CSC
Volume 49, Number 7 7 , November 7972 / 771
