A few things to remember when submitting samples: 
 

• Please label all samples and blanks.

• Please include a full list of the samples and attach it to the sample submission form.

• We do not need a large sample. For solids we generally prefer 100-500 mg, but we can easily work with less; as long as you can weigh it accurately, we can measure it. For liquids/solutions submitted, the necessary amount is concentration dependent and determined by the sensitivity of the instrument for the element to be measured. That said, for a typical biological sample the same rule holds as for solids: if you can determine the accurate sample volume submitted we can probably determine the elemental concentration!

• Solid samples must be digested before measurement, we offer this service for a small fee (see Pricing).  We do not recommend digesting your samples yourself, but if you feel strongly about this, please look at the protocol below. While the protocol is sufficient to digest many types of samples, we suggest that you talk with us before starting your digestions to ensure that they do not require a more complicated digestion to obtain a homogeneous solution.

• If shipping your samples please prepare all samples on dry ice.

Water and Tool Selection

Doubly deionized (DDI) water should be used whenever diluting samples or rinsing labware. If this is not available, please include a sample of the water used.

Metal contamination is a potential hazard when measuring at such high precisions, so to avoid accidental metal contamination avoid metal tools when collecting and preparing samples, non-metal tools should be pre-treated prior to use, procedure under “Pre-treatment” section below.

Pre-Treatment of Glass and Plasticware

• For plastic storage vessels, it is sufficient to fill the vessels with 1% nitric acid for at least 24 hours, before rinsing them with DDI water and using them for sample storage.
• Clean glassware should be soaked in 10% nitric acid for several days and then stored in 2.5% nitric acid.

For Inorganic/Non-Biological samples

If necessary, and possible, clean the sample material to remove all external purities.

Accurately weigh on a precision balance (+/- 0.1 mg) or measure the material directly into 15 ml centrifuge tubes (metal free, VWR, catalog number 89049-170), prior to digestion.

For Biological Samples

• For animal tissues – samples should be weighed on a precision balance (+/- 0.1 mg) and digested with concentrated HNO3 (trace metal grade, Fisher Scientific) in Sarstedt poly-propylene culture tubes (55.516 series).  Ideally the sample weight should be between 50 -100 mg, but we can work with samples as small as 10 mg or as large as 200 mg.

• For blood, adherent cultures, cells, or bacteria – samples should be rinsed twice with an isotonic solution prior to detaching. Ideally, we prefer to have at least 50µl of blood or 10⁶ cells/bacteria per sample submitted. If your samples are in suspension, they should be spun down, resuspended with an isotonic solution, and then spun down again before digestion.  These steps will remove most of the external trace element content.  Cells should be harvested directly into 15 ml (metal free, VWR, catalog number 89049-170) and, after removing aliquots for cell count or protein determination, the cells should be spun down and as much medium removed as possible.

If you do not know where your samples fit in this list or you would just like more advice on how to handle, process, and transport your samples, please Contact Us for assistance at no charge.