AssayIndex

QSC-2601-N8430

Selank · 20 mg declared · Qingdao Sigma Chemical Co., Ltd. · manufactured 12 Jan 2026

CHARACTERISED
Lot code
QSC-2601-N8430
Supplier
QSC — Qingdao Sigma Chemical Co., Ltd.
Compound
Selank
Compound class
Neuroactive and cognitive peptides
Declared label claim
20mg
Manufacture date
12 Jan 2026
Index quarter
2026-Q1
Independent assays
9
Laboratories involved
Janoshik, PeptideMeter
Provenance mix
Supplier-supplied ×9
Section 1

Reproducibility across independent tests

Every report below is an observation of the same physical material. What they disagree about is measurement; what they agree about is the lot. The size of the disagreement is compared against what the contributing laboratories' own repeatability figures predict.

Independent assays 9
Median purity 99.93% n=9
Spread (max − min) 0.54pp n=9
Standard deviation 0.178pp n=9
97.397.898.298.799.299.7100.1This lot (QSC-2601-N8430)This lot (QSC-2601-N8430): Q1 99.81, median 99.93, Q3 99.93, n=9outlier 99.39n=9All SelankAll Selank: Q1 98.60, median 99.13, Q3 99.75, n=112n=112 Purity (% area)
Figure 1. This lot's independent purity results against the whole Selank record set in the index. The vertical line is the index acceptance specification for the neuroactive and cognitive peptides class, 99.0 % area. A narrow box on the top row against a wide box on the bottom row is the ideal reading: it means the disagreement between lots is much larger than the disagreement within this one.
Section 2

Member reports 9

Every report the index holds on this lot. Each is a page carrying its own chromatogram, mass spectrum, mass balance, provenance and caveats.

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041639QSC-2601-N8430Janoshik2026-Q199.816.37Supplier-supplied0PASS
AX-2026-041640QSC-2601-N8430Janoshik2026-Q199.936.96Supplier-supplied0PASS
AX-2026-041641QSC-2601-N8430Janoshik2026-Q199.936.3199.5Supplier-supplied0PASS
AX-2026-041642QSC-2601-N8430PeptideMeter2026-Q199.777.17Supplier-supplied1MARGINAL
AX-2026-041643QSC-2601-N8430PeptideMeter2026-Q199.906.68Supplier-supplied1MARGINAL
AX-2026-041644QSC-2601-N8430Janoshik2026-Q199.396.80106.8Supplier-supplied0PASS
AX-2026-041645QSC-2601-N8430Janoshik2026-Q199.936.62Supplier-supplied0PASS
AX-2026-041646QSC-2601-N8430Janoshik2026-Q199.935.61Supplier-supplied0PASS
AX-2026-041647QSC-2601-N8430Janoshik2026-Q199.936.22Supplier-supplied0PASS
Section 3

By laboratory

Where more than one laboratory assayed this lot, the difference between them is a paired observation of their relative bias — the same material, the same time window, different instruments. Those pairs are what the index's bias estimates are built from.

LaboratoryReportsPurity results (% area)MedianGradientPublished bias (pp)Bias-adjusted
Janoshik799.81, 99.93, 99.93, 99.39, 99.93, 99.93, 99.9399.9330min+0.0099.93
PeptideMeter299.77, 99.9099.8428min-0.0599.89

This lot contributes 1 paired comparison to the inter-lab analysis.

Section 4

The supplier's certificate for this lot

One number the supplier wrote, beside the median of the numbers other people measured on the same physical material. That comparison is only available because the index groups by lot.

FigureSupplier COAThis reportIndex note
Purity (% area)99.9099.81divergence -0.03 pp vs batch median
Total impurities (% area)not stated0.19
Largest single impurity (% area)not stated0.12
Water (%)not stated6.37
Counter-ion (%)6.65.06
Peptide content (%w/w)89.3not determined
Endotoxin (EU/mg)not stated0.51
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Impurity fingerprint

The named impurities reported across this lot's assays, with how consistently each was seen. A fingerprint is what allows two lot numbers held by different companies to be identified as one bulk.

Named impurityReported inMedian % areaRange
diketopiperazine (−18 Da)9 / 90.030.02–0.13
tuftsin fragment (−417 Da)7 / 90.070.05–0.12
acetyl adduct (+42 Da)6 / 90.040.01–0.30
des-Thr (−101 Da)1 / 90.10
Section 7

What this rollup does not establish