Where it fits
When to send this one in: the nominal rating on a filter does not match how it behaves in your process, a new supplier can only offer catalogue numbers, or a media maker needs objective third-party performance data for a new product. This service answers exactly one question — in the nanometre range, how much does this filter actually hold back.
Key characteristics
Three challenge particle families are available: gold nanoparticles (AuNP), polystyrene latex (PSL) and silica (SiO₂), in the 5 nm to 60 nm range. Particle size is chosen from the filter nominal rating and the target process rather than fixed in advance for every job.
Testing runs in the customer-specified chemistry and flow, not on pure water as a stand-in — the same filter behaves differently in UPW and in a process chemical. Three bottles are sampled upstream and three downstream, and the report gives mean and standard deviation together; single-point data at this scale is not trustworthy, and the triplicate sampling is deliberate.
Detection is by differential mobility analyser with condensation particle counter (DMA-CPC); for gold nanoparticle runs, upstream and downstream gold is quantified by inductively coupled plasma mass spectrometry (ICP-MS / ICP-QQQ, detection limit on the order of 1 ppt).
Choosing between options
These four are the ones customers most often conflate, and the boundaries are actually clear:
| Service | Question it answers | What you send |
|---|---|---|
| Nanoparticle retention testing (this) | How much does it retain in the nanometre range? | The filter itself |
| Cartridge performance testing | How does it do on retention, integrity, flow and capacity together? | New or used cartridges of one model |
| Filter cleanliness testing | How much does the filter itself release? | New and used filters, ideally as a pair |
| Extractables and leachables testing | What does this material release into my chemistry? | Filters, tubing, packaging and other wetted parts |
Operation & change-out
What to send: the filter itself, disposable or cartridge format. Please state the nominal rating, the actual process chemistry and the target flow rate — those three determine particle type, particle size and test conditions, and without them the test can only run on assumed conditions. Turnaround is confirmed with the quotation from the scope and sample count; samples are held for one month after closure before disposal.