AssayIndex

AX-2025-019136

PEG-MGF · 2 mg declared · Tianjin Finder Chemical Co., Ltd. · lot TFC-2507-M4201

MARGINALIDENTITY CONSISTENT
Report ID
AX-2025-019136
Compound
PEG-MGF
Compound class
Growth-hormone axis peptides
Supplier
TFC — Tianjin Finder Chemical Co., Ltd.
Batch / lot
TFC-2507-M4201
Declared label claim
2mg
Laboratory
VendorInvestigate
Assay date
23 Aug 2025
Submitted
31 Aug 2025
Quarter
2025-Q3
Submitter
t.vanhecke
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the growth-hormone axis 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, 32 min gradient, 214 nm96.87% area≥ 92.0PASS
Total impuritiesRP-HPLC, sum of reported peaks3.13% area≤ 8.0PASS
Largest single impurityRP-HPLC — di-PEGylated species2.15% area≤ 1.00FAIL
Identity — theoretical monoisotopic masscalculated from molecular formula7894.0000Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)7894.0268Da—NOT TESTED
Mass accuracyobserved vs theoretical+3.4ppm± 15PASS
Peptide contentnot ordered on this submissionnot determined—required to check label claimNOT TESTED
Water contentKarl Fischer, coulometric, duplicate4.30%≤ 9.0PASS
Counter-ion (acetate)anion-exchange ion chromatography1.43%≤ 12.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.90%—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 backgroundOff-white lyophilised cake, intact—white to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear after 90 s gentle swirling, no particulates—clear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration5.51—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 32 min gradient18.26min18.30 ± 0.80 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.11—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²27,718—≥ 20,000PASS
Resolution to nearest impurityvs hydrolysed linker1.71—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.

0969193829073876 PEG-MGF18.26 min · 96.87 % 20.2317.4912.27 same trace · ×20 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 32 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 27,718, and skew follows the reported asymmetry factor of 1.11. 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 2.15 % impurity against a 96.87 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1PEG-MGF — main peak18.264,708,18296.87—
2di-PEGylated species20.23104,4972.15+5000.000
3hydrolysed linker17.4924,7880.51+18.011
4free mPEG20.8413,1230.27-2886.512
5free MGF (unconjugated)12.279,7210.20-5007.488
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 7894.0000 Da, computed from conjugate (24-mer + 5 kDa mPEG). All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100725850975110012251350 [M+8H]8+987.76[M+7H]7+1128.73[M+9H]9+878.12 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 7894.0268 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 (%)
10+790.4073790.41000.00277.9
9+878.1184878.12140.003050.9
8+987.7573987.76060.0033100.0
7+1128.72161128.72540.003851.6
6+1316.67391316.67840.00457.9
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)98.596.87divergence +0.47 pp vs batch median
Total impurities (% area)not stated3.13
Largest single impurity (% area)not stated2.15
Water (%)3.04.30
Counter-ion (%)not stated1.43
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)0.25not determined
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
Buyer-sourced
Evidentiary weight
Strongest available evidence in this index.
Chain of custody
Retail purchase → submitter (ambient, 21 d) → laboratory (courier, cold pack, 9 d) → assay.
Assay date
23 Aug 2025
Submitted to the index
31 Aug 2025
Laboratory
VendorInvestigate, Riga, Latvia
Method basis
32 min gradient · high-resolution MS
Verification status
IDENTITY CONSISTENT
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 TFC-2507-M4201 n=10

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-019133TFC-2507-M4201Janoshik2025-Q398.283.5696.7Supplier-supplied2MARGINAL
AX-2025-019134TFC-2507-M4201PeptideMeter2025-Q397.543.86105.1Supplier-supplied2MARGINAL
AX-2025-019135TFC-2507-M4201Nordanalyt2025-Q398.054.1993.5Supplier-supplied2MARGINAL
AX-2025-019137TFC-2507-M4201Janoshik2025-Q398.093.38102.7Supplier-supplied2MARGINAL
AX-2025-019138TFC-2507-M4201Nordanalyt2025-Q398.374.23—Supplier-supplied2MARGINAL
AX-2025-019139TFC-2507-M4201Kestrel2025-Q397.774.0294.8Supplier-supplied2MARGINAL
AX-2025-019140TFC-2507-M4201Janoshik2025-Q398.013.8092.6Supplier-supplied2MARGINAL
AX-2025-019141TFC-2507-M4201Janoshik2025-Q398.023.7595.3Supplier-supplied2MARGINAL
AX-2025-019142TFC-2507-M4201Janoshik2025-Q398.043.90—Supplier-supplied2MARGINAL

Cross-sections

Other recent PEG-MGF records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042526ERPERP-2509-K6500PeptideMeter2026-Q198.364.8797.1Supplier-supplied1MARGINAL
AX-2026-042528ERPERP-2509-K6500Janoshik2026-Q198.085.5089.3Supplier-supplied2MARGINAL
AX-2026-042527ERPERP-2509-K6500Kestrel2026-Q197.924.96—Supplier-supplied1MARGINAL
AX-2026-043130SSASSA-2505-U6896VendorInvestigate2025-Q496.172.67—Buyer-sourced0PASS
AX-2026-043131SSASSA-2505-U6896Janoshik2025-Q495.812.9596.2Supplier-supplied0PASS
AX-2025-020576SSASSA-2505-U6896Medutest2025-Q496.302.53—Supplier-supplied0PASS
AX-2025-020575SSASSA-2505-U6896Medutest2025-Q496.042.63—Supplier-supplied1FAIL
AX-2025-020577SSASSA-2505-U6896VendorInvestigate2025-Q495.712.67—Buyer-sourced0PASS
Other recent TFC records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041932SemaglutideTFC-2604-X4301Janoshik2026-Q398.884.31—Supplier-supplied0PASS
AX-2026-042067SS-31 (Elamipretide)TFC-2604-Y7472Kestrel2026-Q398.664.44—Supplier-supplied1MARGINAL
AX-2026-042057SermorelinTFC-2605-Y6440Janoshik2026-Q398.683.9498.3Supplier-supplied0PASS
AX-2026-041936SemaglutideTFC-2604-X4301PeptideMeter2026-Q398.624.30—Buyer-sourced1MARGINAL
AX-2026-041973Humanin (HNG)TFC-2605-U5564Janoshik2026-Q399.627.03—Supplier-supplied2FAIL
AX-2026-041980Humanin (HNG)TFC-2605-U5564Janoshik2026-Q399.907.0188.6Supplier-supplied2MARGINAL
AX-2026-041961TirzepatideTFC-2605-G5134Medutest2026-Q398.257.11—Supplier-supplied2MARGINAL
AX-2026-042068SS-31 (Elamipretide)TFC-2604-Y7472Medutest2026-Q398.713.6392.9Supplier-supplied2MARGINAL