AssayIndex

AX-2026-041521

Dihexa · 5 mg declared · Qingdao Sigma Chemical Co., Ltd. · lot QSC-2512-D5887

PASSIDENTITY CONSISTENT
Report ID
AX-2026-041521
Compound
Dihexa
Compound class
Neuroactive and cognitive peptides
Supplier
QSC — Qingdao Sigma Chemical Co., Ltd.
Batch / lot
QSC-2512-D5887
Declared label claim
5mg
Laboratory
Janoshik Analytical
Assay date
05 Apr 2026
Submitted
22 Apr 2026
Quarter
2026-Q2
Submitter
j.girard
Sample provenance
Laboratory-retained
Section 1

Results

Measured against the index acceptance specification for the neuroactive and cognitive peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 30 min gradient, 214 nm99.64% area≥ 98.5PASS
Total impuritiesRP-HPLC, sum of reported peaks0.36% area≤ 1.5PASS
Largest single impurityRP-HPLC — des-hexanoyl (−98 Da)0.21% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula504.3312DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)504.3333DaNOT TESTED
Mass accuracyobserved vs theoretical+4.2ppm± 15PASS
Peptide contentnot ordered on this submissionnot determinedrequired to check label claimNOT TESTED
Water contentKarl Fischer, coulometric, duplicate6.16%≤ 12.0PASS
Counter-ionno ionisable counter-ion expectedN/Anot applicableNOT TESTED
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.40%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundWhite lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration7.152.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient12.16min12.24 ± 0.30 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.080.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²59,582≥ 20,000PASS
Resolution to nearest impurityvs [D-Ile]-epimer0.69no index criterionREPORTED
Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

02226445266798905 Dihexa12.16 min · 99.64 % 9.7412.4214.46 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 30 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 59,582, and skew follows the reported asymmetry factor of 1.08. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.21 % impurity against a 99.64 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Dihexa — main peak12.164,842,81399.64
2des-hexanoyl (−98 Da)9.7410,2070.21-98.074
3free acid (+1 Da)12.424,8600.10+0.984
4[D-Ile]-epimer12.021,4580.030.000
5hexanoyl bis-adduct (+98 Da)14.469720.02+98.074
Closure check — purity + Σ impurities 100.00CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 3

Mass spectrum and identity

Theoretical monoisotopic mass 504.3312 Da, computed from C27H44N4O5. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100475500525550575 [M+1H]1+505.34 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 504.3333 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.
ChargeTheoretical m/zObserved m/zΔ m/zRel. abundance (%)
1+505.3385505.34060.0021100.0
Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

FigureSupplier COAThis reportIndex note
Purity (% area)99.9099.64divergence +0.26 pp vs batch median
Total impurities (% area)0.100.36
Largest single impurity (% area)0.070.21
Water (%)not stated6.16
Counter-ion (%)not statedN/A
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance
Laboratory-retained
Evidentiary weight
Provenance documented, selection uncontrolled.
Chain of custody
Laboratory retained sample (−20 °C, 6 d since original receipt) → re-assay.
Assay date
05 Apr 2026
Submitted to the index
22 Apr 2026
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
IDENTITY CONSISTENT
Section 6

Annotations 2

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

Single records do not establish trends. Where this supplier's quarterly medians are stable across four quarters, a result like this reads as the process rather than the draw — and the timeline page is where to check that.
retest_date
A retest date on the certificate would tell you what the supplier is actually asserting about stability. Purity at 99.64 % on assay day is a starting condition, not a shelf life.
Section 7

Related records

Same batch — lot QSC-2512-D5887 n=1

This is the only report on this lot. One report is not a batch characterisation.

Other recent Dihexa records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041370WWBWWB-2601-C4091Kestrel2026-Q299.9311.05Buyer-sourced0PASS
AX-2025-018407WWBWWB-2507-N1598Janoshik2025-Q399.619.31Buyer-sourced0PASS
AX-2025-019342HYBHYB-2501-T6290VendorInvestigate2025-Q299.577.16Buyer-sourced1MARGINAL
AX-2025-018408WWBWWB-2507-N1598Janoshik2025-Q399.798.96Buyer-sourced0PASS
AX-2025-019344HYBHYB-2501-T6290Kestrel2025-Q299.936.63Buyer-sourced0PASS
AX-2025-019343HYBHYB-2501-T6290VendorInvestigate2025-Q299.396.8396.2Buyer-sourced0PASS
AX-2025-019345HYBHYB-2501-T6290Kestrel2025-Q299.936.79Buyer-sourced0PASS
AX-2025-019340HYBHYB-2501-T6290Kestrel2025-Q299.717.1191.7Buyer-sourced0PASS
Other recent QSC records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041599CJC-1295 (no DAC)QSC-2606-V7416VendorInvestigate2026-Q397.963.52Buyer-sourced1FAIL
AX-2026-041601CJC-1295 (no DAC)QSC-2606-V7416Kestrel2026-Q398.334.10Buyer-sourced1MARGINAL
AX-2026-041602CJC-1295 (no DAC)QSC-2606-V7416VendorInvestigate2026-Q398.363.38101.8Buyer-sourced1MARGINAL
AX-2026-041477TriptorelinQSC-2607-C5749Nordanalyt2026-Q399.533.42Buyer-sourced0PASS
AX-2026-041600CJC-1295 (no DAC)QSC-2606-V7416Nordanalyt2026-Q397.744.91100.9Buyer-sourced1FAIL
AX-2026-041603CJC-1295 (no DAC)QSC-2606-V7416PeptideMeter2026-Q398.434.20Buyer-sourced1MARGINAL
AX-2026-041606CJC-1295 (no DAC)QSC-2606-V7416Janoshik2026-Q398.033.58Buyer-sourced1MARGINAL
AX-2026-041585LiraglutideQSC-2605-W7381Medutest2026-Q399.595.0992.8Laboratory-retained0PASS