Microanalysis Lab Sample Submission Guidelines
Sample Purity:The determination of the concentration of elements in your sample is based upon the direct weight of the the material sampled. Therefore, it is very important that samples be dry, free of foreign substances such as dust, rust, hair, aluminum foil, parafilm, and paper filter fibers ( the most common contaminant). Microscopic inspections have shown that over half of the samples submitted are obviously contaminated.
Most journals require 0.40% for each element. For comparison, NIST standards are 0.03%. Typical compounds submitted have errors ranging from 0.05% to 0.45%. These compounds have all gone through several stages of purification. Let's say while putting your sample into a vial a speck of graphite from your pencil fell into the vial and blended in with your yellow crystals. Let's also say that the speck of graphite weighs 100 µg ( that's really a large speck by the way). The nominal sample size for CHN is 2000 µg. If the speck is taken as part of the sample, then there is a 5% error in the weight. So you see, it doesn't take much to throw the result off.
Sample Size:The actual amount of sample needed depends on the concentration of elements to be detected. To avoid confusion, listed below are the requirements for minimum amount of sample needed per analysis.
|2.0 – 3.0 mg recoverable material/single analysis in flat bottom ½ dram(12x35mm)(32843901)|
|5.0 – 6.0 mg recoverable material/ duplicate analysis in flat bottom ½ dram(12x35mm)(32843901)|
|10.0 – 15.0 mg recoverable material/single analysis|
|20.0 – 25.0 mg recoverable material/ duplicate analysis, this will depend on the theoretical values of the carbon, hydrogen and nitrogen in the actual sample submitted for analysis|
(liquid (non-aqueous), non-routine/air sensitive/unstable)
|It is recommended the student bring at least 2 vials of liquid material in the following vials: V-vial (0.3ml)(13x32mm)(32NL0890)(reactive vial) OR Flat bottom ½ dram vial(12x35mm)(32843901)
For air sensitive materials please bring/submit a minimum of 2 air sensitive capsules for analysis. Please make sure the air sensitive capsule weights are between 2 and 2.5 mg of material.
Please schedule an appointment with the CHN analyst before submitting samples.
|2 - 10.0 mg recoverable material|
|It is recommended the student load at least 10 mg in pre-weighed Al capsule|
|For Al analysis: It is recommended the student load at least 10 mg in pre-weighed tin (Sn) capsule|
|10.0 ml / element recoverable material|
|contact Elizabeth Eves|
(unstable or air sensitive)
|5.0 - 10.0 mg recoverable material in flat bottom ½ dram(12x35mm)(32843901) Please schedule an appointment with the halide analyst before submitting samples.|
NOTE: THE WEIGHT LISTED IS THE AMOUNT THAT MUST BE REMOVED FROM THE SAMPLE VIAL - NOT THE AMOUNT PUT INTO THE SAMPLE VIAL!
Again, these are the minimum sample sizes needed. It is in the users' best interest to submit enough sample for duplicate analyses. Occasionally analyses will be repeated to verify results.
Even though there is a sample disposal fee for OUTSIDE samples, OUTSIDE users should still submit extra sample since there will be a disposal fee even for empty bottles.
SPECIAL NOTE FOR AIR SENSITIVE CAPSULES: Since the lab has no feasible way of extracting excess sample, it is important to put in as close to the minimum weight as possible. Only analyses for metals can be diluted. In other words, CHN or HALIDES analyses of overfilled capsules could lead to erroneous results. Lettered bottles are for CHN's. One capsule should be submitted for each determination - HALIDE, METAL, or CHN.
Sample Containers:Containers should be clean and all surfaces inert to your sample.
| solids, powders, fibers||flat-bottomed (1) dram vial||<0.75" diameter|
| liquids or extremely small samples||v-vial||<0.75" diameter|
| predissolved, aqueous||10-100 ml||any size|
All containers must have the backside of vial free from tape or other label material. It is best to write on vial surface with a Sharpie marker and apply transparent tape over the written portion. It is important to have sample ID on sample vial container not the vial cap. Sample ID should follow this format: initials - ###A (Ex. = JL - 123A). Please make sure your sample id on the vial and the online request match. This will avoid any confusion that may occur
Outside users should follow same ID format but also include School initials & advisor's last name.
(Ex. = JL - 123A MSU - Johnson or JG - 047C UK - Smith)
These should also be placed on your sample submission card to avoid mixing of samples.