AX-2026-041581

Selank · 20 mg declared · Qingdao Sigma Chemical Co., Ltd. · lot QSC-2601-N7209

PASSIDENTITY CONSISTENT

Report ID: AX-2026-041581
Compound: Selank
Compound class: Neuroactive and cognitive peptides
Supplier: QSC — Qingdao Sigma Chemical Co., Ltd.
Batch / lot: QSC-2601-N7209
Declared label claim: 20mg
Laboratory: Janoshik Analytical
Assay date: 11 Feb 2026
Submitted: 19 Feb 2026
Quarter: 2026-Q1
Submitter: c.novak
Sample provenance: Buyer-sourced

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.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 30 min gradient, 214 nm	99.78	% area	≥ 99.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.22	% area	≤ 1.0	PASS
Largest single impurity	RP-HPLC — tuftsin fragment (−417 Da)	0.15	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	751.4402	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	751.4352	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-6.6	ppm	± 15	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	6.07	%	≤ 12.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	7.45	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.97	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	White lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear after 90 s gentle swirling, no particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	4.19	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	6.47	min	6.42 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.15	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	56,838	—	≥ 20,000	PASS
Resolution to nearest impurity	vs diketopiperazine (−18 Da)	1.62	—	no index criterion	REPORTED

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.

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 56,838, and skew follows the reported asymmetry factor of 1.15. 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 0.15 % impurity against a 99.78 % main peak is a line two pixels tall; the main peak runs off-scale there by design.

#	Peak	RT	Area (µV·s)	% area	Δ mass (Da)
1	Selank — main peak	6.47	4,849,617	99.78	—
2	tuftsin fragment (−417 Da)	5.85	7,290	0.15	-417.235
3	diketopiperazine (−18 Da)	6.65	2,430	0.05	-18.011
4	acetyl adduct (+42 Da)	6.81	972	0.02	+42.011
Closure check — purity + Σ impurities				100.00	CLOSES

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.

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 751.4352 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.

Charge	Theoretical m/z	Observed m/z	Δ m/z	Rel. abundance (%)
2+	376.7274	376.7249	-0.0025	52.1
1+	752.4475	752.4425	-0.0050	100.0

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.

Figure	Supplier COA	This report	Index note
Purity (% area)	99.90	99.78	divergence -0.03 pp vs batch median
Total impurities (% area)	not stated	0.22
Largest single impurity (% area)	not stated	0.15
Water (%)	4.6	6.07
Counter-ion (%)	8.7	7.45
Peptide content (%w/w)	86.1	not determined
Endotoxin (EU/mg)	0.39	not determined
Method stated on certificate	YES	—	column, 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: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → third-party forwarder (31 d) → laboratory (courier, cold pack, 12 d) → assay.
Assay date: 11 Feb 2026
Submitted to the index: 19 Feb 2026
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: IDENTITY CONSISTENT

What this report does not establish

How much of the named compound is in the vial. Peptide content was not determined, so recovered mass cannot be calculated and the label claim cannot be checked.
That the material is free of bacterial endotoxin. Endotoxin was not measured. No chromatographic result bears on it.
That the material is sterile. Sterility was not tested.
That any other vial in the same lot has the same composition. One vial was tested. Within-lot vial-to-vial variation in this index has a median of 0.28 pp and a 90th percentile of 0.74 pp.
That any other lot from the same supplier has the same composition. Batch-to-batch variation is larger than within-batch variation for every supplier here.
That the material is suitable for administration to a human or an animal. These are research compounds. No result on this site is a safety assessment and the index takes no position on use.
That the material was manufactured by the supplier that sold it. Contract synthesis is normal in this market and twenty-nine batches in the index fingerprint to a bulk from a different company than the one named on the label.

Section 6

Annotations 3

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.

wide_iqr19 Feb 2026

A single result at 99.78 % is one draw. What makes a supplier's process legible is the spread across its lots, and that is on the scorecard rather than here. This record is one good point in a distribution worth reading whole.

quarter_over_quarter19 Feb 2026

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.

lal_assay19 Feb 2026

The test is cheap relative to the material and slow relative to nothing. A kinetic chromogenic determination is under an hour of instrument time.

Section 7

Related records

Same batch — lot QSC-2601-N7209 n=3

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041582	QSC-2601-N7209	Medutest	2026-Q1	99.93	6.60	96.4	Buyer-sourced	0	PASS
AX-2026-041583	QSC-2601-N7209	VendorInvestigate	2026-Q1	99.93	6.56	100.9	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Selank records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042858	GGPeps	GGPE-2603-J2447	VendorInvestigate	2026-Q3	98.87	8.85	99.4	Buyer-sourced	0	FAIL
AX-2026-042859	GGPeps	GGPE-2603-J2447	PeptideMeter	2026-Q3	98.92	9.48	103.5	Buyer-sourced	0	FAIL
AX-2026-041759	TFS	TFS-{CAT}-1712	Janoshik	2026-Q2	99.93	8.13	102.2	Buyer-sourced	0	PASS
AX-2026-042912	GGPeps	GGPE-2601-J3130	Janoshik	2026-Q2	99.75	9.44	89.7	Buyer-sourced	1	MARGINAL
AX-2026-041760	TFS	TFS-{CAT}-1712	Janoshik	2026-Q2	99.82	7.70	—	Buyer-sourced	0	PASS
AX-2026-041752	TFS	TFS-{CAT}-1712	Medutest	2026-Q2	99.63	7.43	—	Buyer-sourced	1	FAIL
AX-2026-042915	GGPeps	GGPE-2601-J3130	PeptideMeter	2026-Q2	99.53	10.03	—	Buyer-sourced	0	PASS
AX-2026-042910	GGPeps	GGPE-2601-J3130	VendorInvestigate	2026-Q2	99.62	9.21	105.0	Buyer-sourced	0	PASS

Other recent QSC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041599	CJC-1295 (no DAC)	QSC-2606-V7416	VendorInvestigate	2026-Q3	97.96	3.52	—	Buyer-sourced	1	FAIL
AX-2026-041601	CJC-1295 (no DAC)	QSC-2606-V7416	Kestrel	2026-Q3	98.33	4.10	—	Buyer-sourced	1	MARGINAL
AX-2026-041602	CJC-1295 (no DAC)	QSC-2606-V7416	VendorInvestigate	2026-Q3	98.36	3.38	101.8	Buyer-sourced	1	MARGINAL
AX-2026-041477	Triptorelin	QSC-2607-C5749	Nordanalyt	2026-Q3	99.53	3.42	—	Buyer-sourced	0	PASS
AX-2026-041600	CJC-1295 (no DAC)	QSC-2606-V7416	Nordanalyt	2026-Q3	97.74	4.91	100.9	Buyer-sourced	1	FAIL
AX-2026-041603	CJC-1295 (no DAC)	QSC-2606-V7416	PeptideMeter	2026-Q3	98.43	4.20	—	Buyer-sourced	1	MARGINAL
AX-2026-041606	CJC-1295 (no DAC)	QSC-2606-V7416	Janoshik	2026-Q3	98.03	3.58	—	Buyer-sourced	1	MARGINAL
AX-2026-041585	Liraglutide	QSC-2605-W7381	Medutest	2026-Q3	99.59	5.09	92.8	Laboratory-retained	0	PASS