AssayIndex

AX-2025-018890

Selank · 10 mg declared · Qingdao Sigma Chemical Co., Ltd. · lot QSC-2502-N9962

PASSVERIFIED
Report ID
AX-2025-018890
Compound
Selank
Compound class
Neuroactive and cognitive peptides
Supplier
QSC — Qingdao Sigma Chemical Co., Ltd.
Batch / lot
QSC-2502-N9962
Declared label claim
10mg
Laboratory
Janoshik Analytical
Assay date
05 May 2025
Submitted
10 May 2025
Quarter
2025-Q2
Submitter
Contributor #K-1948
Sample provenance
Supplier-supplied
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 nm99.81% area≥ 99.0PASS
Total impuritiesRP-HPLC, sum of reported peaks0.19% area≤ 1.0PASS
Largest single impurityRP-HPLC — acetyl adduct (+42 Da)0.09% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula751.4402Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)751.4379Da—NOT TESTED
Mass accuracyobserved vs theoretical-3.0ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance82.34%w/w—NOT TESTED
Target-compound contenttotal peptide content × purity82.18%w/w—NOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen12.98mg10 mg declaredNOT TESTED
Recovered target peptidegross fill × target content10.667mg10 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim106.7%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate10.03%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography6.90%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.73%—NOT TESTED
Endotoxinkinetic chromogenic LAL0.37EU/mg≤ 5.0PASS
Sterilitymembrane filtration, USP <71>, 14 dNo growth at 14 d—no growthPASS
Appearancevisual, diffuse light, black and white backgroundWhite cake, partial shrinkage from vial wall—white to off-white intact cakeFAIL
Reconstitution clarityreconstituted per submitter procedureClear with a single visible fibre—clear, no visible particulatesFAIL
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.91—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient6.53min6.42 ± 0.25 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.12—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²65,840—≥ 20,000PASS
Resolution to nearest impurityvs des-Thr (−101 Da)2.49—no 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.

0428385661284917132 Selank6.53 min · 99.81 % 6.87 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 65,840, and skew follows the reported asymmetry factor of 1.12. 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 0.09 % impurity against a 99.81 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Selank — main peak6.534,851,07599.81—
2acetyl adduct (+42 Da)6.874,3740.09+42.011
3des-Thr (−101 Da)6.272,4300.05-101.048
4tuftsin fragment (−417 Da)5.912,4300.05-417.235
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 751.4402 Da, computed from C33H57N11O9. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100325425525625725825 [M+1H]1+752.45[M+2H]2+376.73 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 751.4379 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 (%)
2+376.7274376.7262-0.001250.0
1+752.4475752.4452-0.0023100.0
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.

ComponentDetermination%w/w of cake
WaterKarl Fischer10.03
Counter-ion (acetate)ion chromatography6.90
Residual solvent + inorganic residueestimated0.73
Total peptide contentby difference82.34
Total100.00 CLOSES

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)99.9099.81divergence +0.09 pp vs batch median
Total impurities (% area)0.100.19
Largest single impurity (% area)0.070.09
Water (%)not stated10.03
Counter-ion (%)not stated6.90
Peptide content (%w/w)not stated82.34
Endotoxin (EU/mg)0.440.37
Method stated on certificateNO—no method section — the result cannot be reconciled against any other
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
Supplier-supplied
Evidentiary weight
Weaker evidence. Read with the caveat below.
Chain of custody
Supplier despatch → laboratory direct (courier, cold pack, 5 d) → assay. Submitter did not handle the vial.
Assay date
05 May 2025
Submitted to the index
10 May 2025
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
VERIFIED
Section 6

Annotations

No annotations on this record. Annotations are short signed technical comments from index contributors; see how to contribute.

Section 7

Related records

Same batch — lot QSC-2502-N9962 n=1

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

Cross-sections

Other recent Selank records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042737GGPepsGGPE-2603-J9708Janoshik2026-Q398.409.1497.4Buyer-sourced0FAIL
AX-2026-042804GGPepsGGPE-2602-G2056Janoshik2026-Q398.507.97—Supplier-supplied0FAIL
AX-2026-042803GGPepsGGPE-2602-G2056Janoshik2026-Q398.488.01—Laboratory-retained1FAIL
AX-2026-042802GGPepsGGPE-2602-G2056Janoshik2026-Q398.747.0996.0Supplier-supplied0FAIL
AX-2026-042796GGPepsGGPE-2602-G2056Janoshik2026-Q398.267.5697.5Buyer-sourced0FAIL
AX-2026-042797GGPepsGGPE-2602-G2056Medutest2026-Q398.467.92—Buyer-sourced0FAIL
AX-2026-042743GGPepsGGPE-2603-J9708Medutest2026-Q399.599.37—Supplier-supplied0PASS
AX-2026-042799GGPepsGGPE-2602-G2056Nordanalyt2026-Q398.778.33—Supplier-supplied0FAIL
Other recent QSC records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041683CJC-1295 (no DAC)QSC-2606-V8637Janoshik2026-Q399.933.6397.1Supplier-supplied1FAIL
AX-2026-041727CJC-1295 with DACQSC-2602-E9474Janoshik2026-Q398.886.62105.3Supplier-supplied1MARGINAL
AX-2026-041728CJC-1295 with DACQSC-2602-E9474VendorInvestigate2026-Q398.427.04—Buyer-sourced1MARGINAL
AX-2026-041734CJC-1295 with DACQSC-2602-E9474Medutest2026-Q399.437.17105.5Supplier-supplied2FAIL
AX-2026-041652LiraglutideQSC-2605-W8602Nordanalyt2026-Q399.336.55—Supplier-supplied0PASS
AX-2026-041730CJC-1295 with DACQSC-2602-E9474PeptideMeter2026-Q398.796.9395.4Supplier-supplied1MARGINAL
AX-2026-041686CJC-1295 (no DAC)QSC-2606-V8637Janoshik2026-Q399.934.04—Supplier-supplied0PASS
AX-2026-041653LiraglutideQSC-2605-W8602VendorInvestigate2026-Q398.825.95—Buyer-sourced0PASS