What changed at QSC in March, and what the company will not say about it

QSC has again declined to identify the facility that synthesises the material it sells. The Journal has now put the question in writing on 18 occasions since 2024, in each case asking only for the name of the synthesis house or an acknowledgement that the company is a reseller. The replies have been courteous and have addressed a different question.

The Journal’s written requests are dated across 18 quarters and were sent to the address the company publishes for commercial enquiries. Four received a reply within a fortnight. Each reply restated the company’s quality claims and none named a facility. One offered a video call, which the Journal declined on the grounds that a video call produces nothing publishable.

The revised document states a detection wavelength of 214 nm, a gradient duration, a column identifier and a threshold of 0.05% of main-peak area. It does not state a reference-standard lot number, and it does not report content, water or counter-ion. On the Journal’s assessment that puts it in the upper quartile of certificates circulating in this market, which says more about the market than about the document.

The distinction that matters here is between a company that will not answer and a company that cannot. A reseller with no visibility into its own supply chain is in a different position from a manufacturer protecting a process, and the two are indistinguishable from the outside — which is precisely why the Journal reports the count of unanswered requests rather than an inference about the reason.

"Printing the threshold costs them nothing and it is the single most useful line you can add," said Dr Adaeze Nwafor, consultant endocrinologist, Leeds. "It converts a number you have to trust into a number you can check."

The change has been recorded in QSC’s dossier, which is reviewed quarterly. Readers holding certificates from this supplier are invited to send them to the standards desk; we compare document sets across time and publish what changes.