Bracketing splits the sequence by acquisition time. Each cal set gets its own curve. Each stretch of samples is read from the cal set before it and the cal set after it.

Bracket calibration sequence Calibration set, samples, calibration set. Each sample block uses the surrounding cal sets. Bracketing  a curve for each stretch of the sequence Ordered by acquisition time. A cal block uses itself. A sample block uses the cal set before it and the cal set after it. Cal set A C1 C2 C3 C4 Samples 1 UNK-01 UNK-02 QC-01 Cal set B C1 C2 C3 C4 Samples 2 UNK-03 UNK-04 BLK 1 Samples 1 use Cal A + Cal B 2 Cal set A and Cal set B each also get their own curve (the cal bottles themselves). Method Calibration mode = Bracketing. Same multi-level doses as initial calibration. Works with ESTD or ISTD. A leading or trailing sample block with only one neighboring cal set uses that set alone.
Cal set A, samples, cal set B, more samples

When to use it

Method Calibration mode = Bracketing. Levels and ISTD links are the same as ESTD or ISTD.

How Quanto cuts the sequence

Samples are ordered by Acquired. Contiguous calibration bottles form a cal set. Everything else (Sample, QC, Blank) forms a sample block.

Block Curve points
Cal set That set only
Sample block Immediately preceding cal set and immediately following cal set
Leading samples (no cal yet) The first cal set only
Trailing samples (no cal after) The last cal set only

QC and blanks ride with the sample block they sit in. They do not start a new bracket.

Independent fits

Two bracket curves Cal set A and Cal set B produce slightly different curves. Samples 1 sit between them. Each bracket keeps its own fit Instrument drift moves Cal B off Cal A. Samples between the two sets share both point clouds. Concentration Response UNK on A+B Cal set A curve Cal set B curve Sample between A and B Disable a point in one bracket without touching the other. Replacement responses stay per bracket.
Two slightly different curves from cal set A and cal set B

Each bracket stores:

Turn a point off in bracket 2 and bracket 1 is unchanged. The calibration plot for a sample shows the points of that sample’s bracket.

Set it up

  1. Build the method as ESTD or ISTD, multi-level.
  2. Set Calibration mode to Bracketing.
  3. Add the sequence in run order (or trust Acquired).
  4. Mark every standard Type Calibration and Dose C1…Cn. Repeat the same dose names in every cal set.
  5. Analyze.

If a sample block has no neighboring calibrations at all, that block is not quantitated.

What bracketing does not do

Open the result’s calibration rows to see which files belong to the current bracket.