Our lab offers an analysis of particle size distribution by laser diffractometry. This analysis measures 101 bins of particle sizes from 0.01 – 2,000 um, to produce a continuous curve result. This data can be aggregated into standard particle size fractions, which are included in our report template.
Before providing us with the samples, they should be prepared by drying, grinding, and passing the sample through a 2 mm sieve. If you need us to grind your samples and sieve for particles over 2 mm, we can provide that service for an additional fee.
| Service (all costs are per sample) | Internal | External |
| Particle Size Analysis in deionized water | $17.72 | $21.26 |
| Particle Size Analysis in alcohol | $36.30 | $43.55 |
| Grinding, sieving, and homogenization | $3.00 | $4.00 |
| Weighing of coarse fraction (>2 mm) | $0.50 | $1.00 |
When you submit your samples to us, please include the appropriate form below, completed and printed with the information we’ll need to process your samples.
FAQs
- How much sample is needed for analysis?
- Analysis by laser diffraction only needs 1/8 of a teaspoon for fine-textured samples per run. Sandy samples may need 1/2 to 1 teaspoon for a run. Our price per sample includes a quality control process that includes two runs that are compared, and then one to two more runs if additional data is needed to determine a representative result. Therefore, we require a minimum of four teaspoons (20 cm3) to be sent per sample to ensure we can conduct the full quality control analysis. If measuring in grams, then 40 grams of a typical soil should be sufficient. Details on the quality control process may be found in Miller and Schaetzl (2012).
- Given the small amount of sample analyzed how can we best ensure the result is representative of the soil/sediment we are trying to measure?
- We recommend that the samples given to us be as large as possible. We would only use a small amount and then can return the unused portion to you. If shipping the samples to us, you may want to minimize weight, and returning the unused portion may not be feasible. In this case, we recommend that you homogenize your original larger sample and then pull one teaspoon of material from at least four different locations within the sample.
- Can samples be shipped in for analysis?
- Generally, yes, but all samples must comply with USDA APHIS regulations for the transport of soil. If the samples do not contain any organic material, then they are considered sediments and are not regulated. A map of counties within the USA where the soil is quarantined and, therefore, cannot be shipped from may be found here: https://www.aphis.usda.gov/plant_health/permits/organism/soil/downloads/Fed-SoilRegs.pdf. Importation of soil from outside the continental USA requires a USDA import permit (PPQ 330), which our lab does not have.
- Where do I send my samples?
- Located near Ames, Iowa: Samples may be dropped off at 2312 Agronomy Hall on Iowa State University’s campus.
- Shipping address:
- GLSI, Department of Agronomy
Iowa State University
c/o Bradley Miller
2104P Agronomy Hall
716 Farm House Lane
Ames, IA 50011-1051
- GLSI, Department of Agronomy
- How will I be billed?
- Internal (Iowa State University) clients need to provide a worktag with their sample submissions. The worktag will be charged when we send you your results.
- External clients will need to be set up with a customer number with Iowa State University for our accounts receivable to issue a bill. The information needed to do this is described in the “External PSA-Order-Form.” After samples are received with the submission form, we will generate and send you an invoice for your records. You will not pay this invoice! Instead, Iowa State University will send you a bill with a payment number for remittance. Please note that Iowa State University billing does not accept credit cards. More information about accepted methods of bill payment may be found at: https://www.ubill.iastate.edu/payments.
For inquiries about this particle size analysis or to arrange a time to bring your samples over, please contact millerba@iastate.edu.
