AssayIndex

AX-2024-004332

Epitalon · 20 mg declared · Qingdao Sigma Chemical Co., Ltd. · lot QSC-2403-Y7501

FAILMETHOD LIMITED
Report ID
AX-2024-004332
Compound
Epitalon
Compound class
Short bioregulator peptides
Supplier
QSC — Qingdao Sigma Chemical Co., Ltd.
Batch / lot
QSC-2403-Y7501
Declared label claim
20mg
Laboratory
Janoshik Analytical
Assay date
20 Jul 2024
Submitted
04 Aug 2024
Quarter
2024-Q3
Submitter
ad.ibarra
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the short bioregulator 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≥ 99.0PASS
Total impuritiesRP-HPLC, sum of reported peaks0.36% area≤ 1.0PASS
Largest single impurityRP-HPLC — aspartimide (−18 Da)0.24% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula390.1387Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)390.1385Da—NOT TESTED
Mass accuracyobserved vs theoretical-0.6ppm± 20PASS
Total peptide contentby difference from the gravimetric mass balance80.10%w/w—NOT TESTED
Target-compound contenttotal peptide content × purity79.81%w/w—NOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen24.30mg20 mg declaredNOT TESTED
Recovered target peptidegross fill × target content19.394mg20 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim97.0%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate6.70%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography13.01%≤ 10.0FAIL
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.19%—NOT TESTED
Endotoxinnot ordered on this submissionnot determined—≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determined—no growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundWhite to pale-yellow cake, intact—white to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulates—clear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.52—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient4.60min4.62 ± 0.20 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.04—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²36,692—≥ 20,000PASS
Resolution to nearest impurityvs β-Asp isomer1.02—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.

0470994171412618835 Epitalon4.60 min · 99.64 % 4.72 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 36,692, and skew follows the reported asymmetry factor of 1.04. 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 0.24 % 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)
1Epitalon — main peak4.604,842,81399.64—
2aspartimide (−18 Da)4.7211,6650.24-18.011
3diketopiperazine (−18 Da)4.762,4300.05-18.011
4Ala-Glu-Asp tripeptide (−57 Da)4.401,9440.04-57.021
5β-Asp isomer4.501,4580.030.000
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 390.1387 Da, computed from C14H22N4O9. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100350375400425450475 [M+1H]1+391.15 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 390.1385 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+391.1460391.1458-0.0002100.0
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 Fischer6.70
Counter-ion (acetate)ion chromatography13.01
Residual solvent + inorganic residueestimated0.19
Total peptide contentby difference80.10
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)99.2599.64divergence -0.67 pp vs batch median
Total impurities (% area)1.090.36
Largest single impurity (% area)not stated0.24
Water (%)5.26.70
Counter-ion (%)9.013.01
Peptide content (%w/w)85.280.10
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYES—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 → submitter (ambient, 9 d) → laboratory (hand-carried, 9 d) → assay.
Assay date
20 Jul 2024
Submitted to the index
04 Aug 2024
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
METHOD LIMITED
Section 6

Annotations 5

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.

diode_array
Photodiode-array spectral homogeneity across the main peak would convert 99.64 % from a good number into a checked one. It is a free measurement on any instrument that already has the detector.
price_per_mg
A retail purchase carries a price, which makes cost per milligram of recovered peptide computable. That is the comparison a buyer actually needs and it exists only for this provenance class.
bland_altman
Where two laboratories tested the same retail lot, the paired difference is a clean estimate of inter-lab bias with no selection term in it at all. Those pairs are the backbone of the agreement analysis.
low_n
Strong provenance does not fix small n. One well-sourced record is still one record, and the batch page says how many others exist for QSC-2403-Y7501.
Section 7

Related records

Same batch — lot QSC-2403-Y7501 n=12

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2024-004330QSC-2403-Y7501Janoshik2024-Q399.926.1488.9Buyer-sourced2MARGINAL
AX-2024-004331QSC-2403-Y7501Medutest2024-Q399.936.10105.3Buyer-sourced1MARGINAL
AX-2024-004333QSC-2403-Y7501Kestrel2024-Q399.935.87106.9Buyer-sourced1MARGINAL
AX-2024-004334QSC-2403-Y7501Janoshik2024-Q399.836.8094.0Buyer-sourced1FAIL
AX-2024-004335QSC-2403-Y7501Janoshik2024-Q399.935.99—Buyer-sourced1MARGINAL
AX-2024-004336QSC-2403-Y7501Medutest2024-Q399.935.91—Buyer-sourced1MARGINAL
AX-2024-004337QSC-2403-Y7501Janoshik2024-Q399.586.52—Buyer-sourced1MARGINAL
AX-2024-004338QSC-2403-Y7501Janoshik2024-Q399.916.90—Buyer-sourced1FAIL
AX-2024-004339QSC-2403-Y7501Medutest2024-Q399.936.33100.2Buyer-sourced1MARGINAL
AX-2024-004340QSC-2403-Y7501Janoshik2024-Q399.796.3989.7Buyer-sourced2MARGINAL
AX-2024-004341QSC-2403-Y7501Nordanalyt2024-Q399.546.5497.4Buyer-sourced1MARGINAL

Cross-sections

Other recent Epitalon records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042008AMBAMB-2602-Y6433Janoshik2026-Q399.308.75105.1Buyer-sourced0PASS
AX-2026-042009AMBAMB-2602-Y6433VendorInvestigate2026-Q399.168.62102.3Buyer-sourced0FAIL
AX-2026-042010AMBAMB-2602-Y6433Janoshik2026-Q399.098.20103.4Laboratory-retained0FAIL
AX-2026-042007AMBAMB-2602-Y6433Janoshik2026-Q399.428.6293.8Buyer-sourced0FAIL
AX-2026-042468HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.81100.8Buyer-sourced0PASS
AX-2026-042463HomopeptideHOMO-2512-A5108Janoshik2026-Q299.937.6893.2Buyer-sourced0FAIL
AX-2026-042041HYBHYB-2603-U7133Janoshik2026-Q299.656.8295.3Buyer-sourced0FAIL
AX-2026-042470HomopeptideHOMO-2512-A5108Janoshik2026-Q299.637.99—Buyer-sourced0FAIL
Other recent QSC records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041599CJC-1295 (no DAC)QSC-2606-V7416VendorInvestigate2026-Q397.963.52—Buyer-sourced1FAIL
AX-2026-041601CJC-1295 (no DAC)QSC-2606-V7416Kestrel2026-Q398.334.10—Buyer-sourced1MARGINAL
AX-2026-041602CJC-1295 (no DAC)QSC-2606-V7416VendorInvestigate2026-Q398.363.38101.8Buyer-sourced1MARGINAL
AX-2026-041477TriptorelinQSC-2607-C5749Nordanalyt2026-Q399.533.42—Buyer-sourced0PASS
AX-2026-041600CJC-1295 (no DAC)QSC-2606-V7416Nordanalyt2026-Q397.744.91100.9Buyer-sourced1FAIL
AX-2026-041603CJC-1295 (no DAC)QSC-2606-V7416PeptideMeter2026-Q398.434.20—Buyer-sourced1MARGINAL
AX-2026-041606CJC-1295 (no DAC)QSC-2606-V7416Janoshik2026-Q398.033.58—Buyer-sourced1MARGINAL
AX-2026-041585LiraglutideQSC-2605-W7381Medutest2026-Q399.595.0992.8Laboratory-retained0PASS