LIMS Quality Control and Mining QA/QC

QC records: materials, tests and limits

Your QC program lives in one place. OnQC holds the definition of each control, and every worksheet that uses it adds its readings, so one QC record builds the history of a material across many runs and tests. Each record carries its category, service group, tests, units and approved acceptance criteria.

Standards / CRMs Certified reference materials compare results with an assigned value: each test carries the certified value and its accepted range.
Controls and blanks A control is a material of known characteristics run with routine samples; a blank detects contamination from reagents, equipment or preparation. Each has its own tests and approved limits.
Duplicates An original and a repeat determination measure precision, with their own acceptance range and percentage error.
QC categories Standard, Control, Blank and Duplicate, plus Replicate and Spike. Category and service group keep the right controls in front of each worksheet.

For example, a standard certified at 10.0 mg/L with an accepted range of 9.0–11.0 mg/L: a reading of 10.4 is inside the range, 11.5 is outside, and both endpoints count as inside.

Controls run with the samples

QC sits in the same worksheet as the samples it checks, so nobody has to match them up afterwards. Controls are picked by category, service group and QC record and placed into existing rows or added as new ones; they can also be inserted automatically from a chosen position at a fixed interval.

Each standard, blank and control is identified by its QC record and linked to the result column's test and unit, and duplicate rows stay paired with their original sample. Once the worksheet is locked and saved, its QC readings join the control's history in OnQC.

What happens when a QC result is locked?

This is the step that protects your results: OnWSH checks every linked QC result as it is locked. Standards, blanks and controls are compared with their QC record's limits; duplicates with their precision criteria. A QC result inside its limits locks straight away and turns dark green, bold and underlined. One outside its limits opens the Control Chart before it can be locked, showing the QC record, test, observed value, target, limits and history.

Cancel The QC cell stays unlocked while the analyst checks the reading, the standard, the instrument or the calculation. The other cells in the selection still lock normally.
Accept with a note An authorized user records the reason and accepts. The cell locks with its QC flag, shows red, bold and underlined, and keeps the note; the recorded value is never changed.
Release protected A test column is not exported to OnLAB while one of its standards, blanks or controls is still unlocked, so unchecked QC cannot slip into a published result.

Accuracy charts and precision control

Trends show up before they become failures. In OnQC, each control and test opens a chart for any period, with the statistics, the list of readings and a read-only view of the source worksheet at hand.

Accuracy Shewhart plots results against the mean with lines at one, two and three standard deviations. X Control adds the reference material's accepted range. Cumulative Sum (CUSUM) plots the accumulated difference between the certified value and successive results.
Precision Replicate Ro plots the difference between duplicate pairs, alongside percentage of replication, range control, range ratio and cumulative sum. Range control works on 20 or more duplicate sets.
Range performance in OnLQC Each duplicate pair's absolute difference is plotted against its mean concentration with a fitted line, showing how precision changes across the concentration range you report.

QC reports, export and release records

When the auditor or the client asks, the evidence is ready. QC reports cover any date range and group of controls, any figure drills down to the readings behind it, and report layouts can be saved and shared with colleagues.

A QC record exports to Excel with its header, certified values, limits and worksheet readings, or to XML to archive it or load it as a new QC record.

Release follows the same discipline: reviewed results and the worksheet are locked before export to OnLAB, and only users with the publishing permission publish. Worksheet result changes are recorded with user and date, each OnLAB job keeps its audit, and LabData shows clients only their published results.

OnConfig assigns permissions by role, and the system audit records application events and user logins. Job results export to CSV, XLSX or XLS for client delivery or further analysis, carrying published values only.

Archive a control and replace a CRM

A new CRM lot never erases the old one's history. The old control is archived: it leaves the working list but keeps all its data, which can be filtered back into view at any time. The replacement is created as a new QC record, copied from the old one if useful so tests, units and settings carry over, and updated with the new lot's certified values and limits; historical readings stay with the original record.

Frequently asked questions

Does accepting an out-of-limit QC change its value?

No. Accepting locks that QC cell with its flag and the note. The value stays exactly as measured and is shown red, bold and underlined, so every reviewer sees the decision.

When does OnWSH check QC limits?

Every time results are locked. Each linked standard, blank, control and duplicate is checked against its QC record; results inside the limits lock straight away and an out-of-range result opens the Control Chart.

How do I replace a CRM lot?

Archive the old control so its history is kept, then create the new lot as a new QC record, copying the old definition if useful, and enter the new lot's certified values and limits. Historical readings stay with the original record.

Does the QC check apply to every instrument?

Yes. The same check at locking applies to results from any of the 150+ connected instruments, from AAS, ICP-OES/MS and XRF to carbon/sulfur analyzers, titrators and balances.

LIMS Quality Control and mining QA/QC