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1 mL and 3 mL cuvettes. Traditional ultraviolet–visible spectroscopy or fluorescence spectroscopy uses samples that are liquid. Often the sample is a solution, with the substance of interest dissolved within. The sample is placed in a cuvette and the cuvette is placed in a spectrophotometer for testing.
Typical sizes are between 30 mL and 3 L. In industrial chemistry they can be much larger and for much larger volumes centrifuges are used. The sloping sides are designed to facilitate the identification of the layers. The tap-controlled outlet is designed to drain the liquid out of the funnel.
A laboratory centrifuge is a piece of laboratory equipment, driven by a motor, which spins liquid samples at high speed. There are various types of centrifuges, depending on the size and the sample capacity.
For example, a blue-top tube is a 5 ml test tube containing sodium citrate as an anticoagulant, used to collect blood for coagulation and glucose-6-phosphate dehydrogenase testing. [5] Small vials used in medicine may have a snap-top (also called a hinge cap) molded as part of the vial.
Cassia flasks, for the analysis of essential oils and aldehyde determination, approx. 100 ml, neck graduated 0–6: 0.1 ml. Erlenmeyer flasks (introduced in 1861 by German chemist Emil Erlenmeyer (1825–1909)) are shaped like a cone, usually completed by the ground joint; the conical flasks are very popular because of their low price (they are ...
For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. These marks are not intended for obtaining a precise measurement of volume (a graduated cylinder or a volumetric flask would be a more appropriate instrument for such a task), but rather an estimation. Most beakers are accurate to ...
The error, give or take 0.1 mL, must be included too. Therefore, the more precise value equates to 36.5 0.1; 36.4 or 36.6 mL. Therefore, there are 3 significant figures can be read from the given graduated cylinder picture. [9] Another example, if the reading is done and the value calculated is set to be 40.0 mL.
Typically, ten-fold dilutions are used, and the dilution series is plated in replicates of 2 or 3 over the chosen range of dilutions. Often 100 μL are plated but also larger amounts up to 1 mL are used. Higher plating volumes increase drying times but often do not result in higher accuracy, since additional dilution steps may be needed. [5]