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Glass Spectrophotometer Tubes ! - what's wrong with them (Aug/09/2007 )

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QUOTE
quartz is uv transparent and good for both uv and visible applications. also, since it is used for cuvettes, will be manufactured to finer tolerances
mdfenko, what do u mean by 'finer tolerances' !? unsure.gif
and is quartz=crystal!

QUOTE
lime glass is not recommended for use in a spectrophotometer but may be usable


Why?! unsure.gif

-strawberry-

QUOTE (strawberry @ Aug 23 2007, 05:01 AM)
QUOTE
quartz is uv transparent and good for both uv and visible applications. also, since it is used for cuvettes, will be manufactured to finer tolerances
mdfenko, what do u mean by 'finer tolerances' !? unsure.gif
and is quartz=crystal!

QUOTE
lime glass is not recommended for use in a spectrophotometer but may be usable
Why?! unsure.gif

finer tolerances refers to attributes such as clarity, regularity of wall thickness, foreign particles, etc.

quartz is a silicate crystal.

lime glass tubes are usually thicker walled than borosilicate and show a general green tinge.

-mdfenko-

what about the ability of getting reactions between the material (glass or quartz) and colors of solutions, particles,.......unsure.gif
i heard once that this may affect the final readings !!

-strawberry-

yes, it does happen. and it may affect the readings. i find that the bradford protein determination leaves a residue behind on the cuvette. we wash the cuvette with alcohol to remove it between all readings.

particulates will scatter the light and cause the appearance of absorbance.

-mdfenko-

thanx mdfenko smile.gif , but which type 'stick' more particulates, glass or the quartz cuvettes?! unsure.gif

-strawberry-

QUOTE (strawberry @ Aug 26 2007, 04:59 AM)
thanx mdfenko smile.gif , but which type 'stick' more particulates, glass or the quartz cuvettes?! unsure.gif

with the bradford method, it didn't appear to matter. both bound a lot of dye so we use disposable plastic for this procedure.

as for what will bind more, it depends on the solution but i think that glass may bind more, in general. you still have to clean any cuvette thoroughly.

-mdfenko-

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