6875 Freezer/Mill
Page 25 of 42
SPEX® SamplePrep LLC
DEC 2015
6.5 Opening, Emptying, and Cleaning Freezer/Mill Vials
(Cont’d)
to warm up gradually, wrapped in several layers of cloth or paper towels. Once the vial is warm,
the stuck end plug can be drawn out by hand or with a pair of pliers. When using pliers to extract
an end plug, rotate the end plug and pull gently, as if unscrewing a bottle-cap. Forcibly rocking
the end plug from side to side can stress the polycarbonate tube and crack it.
CAUTION:
Pressure can develop inside a Freezer/Mill vial as it is warming. As pressure builds,
an end plug can pop out with force and the sample can be lost. For this reason
handle vials with care, and wrap them in paper towel. It is best to open chilled vials
immediately after removing them from the Freezer/Mill.
6.5.2 Emptying a Vial
As soon as the flanged end plug is removed from a cold vial, empty the contents of the vial into a
suitable container, the quicker the better as condensation on a cold sample occurs rapidly. Often
it is helpful to tap the closed end of the vial to release the ground sample. Remember that the
impactor may slide out ahead of the contents or with them, and that the longer the sample is
exposed to air, the more water it will acquire from condensation. Samples which were tacky,
spongy, etc., at room temperature will also return to that state as they warm up, and may
agglomerate.
The impactor will have to be separated from the sample and can be handled with gloved fingers,
a strong magnet, tongs, or pliers. Tools without a good gripping surface are likely to slip off the
impactor. 6870L Accessory Pack included a Magnetic Extractor (6791). This is a rod with a
magnetic tip that can be used to remove the impactor from a vial before emptying the contents.
If some condensation on a cold sample is unacceptable, either wait for the sample vial to warm
up before opening and emptying it, or open and empty a chilled vial in a glove box filled with dry
nitrogen gas.
Small amounts of sample usually adhere to the vial’s impactor, end plugs, and plastic cylinder.
Brushing or scraping these surfaces of the vial can often recover this fraction of the sample.
Again, speed is important to minimize condensation and other effects of warming.
If it is necessary to recover 100% of the sample, let the vial warm up and add some water or
other liquid that will not affect the polycarbonate (see Section 6.5.3). Shake the vial, empty it
onto some filter paper, and rinse again if necessary to recover the entire sample.
6.5.3 Cleaning the Vials
The Freezer/Mill vials may be superficially cleaned quickly and easily by placing them under
running hot water. If the vial is cold a coating of ice will form on the steel parts, but will melt
quickly as the water runs.