AssayIndex

AX-2025-019141

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

MARGINALPARTIAL
Report ID
AX-2025-019141
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
Janoshik Analytical
Assay date
16 Aug 2025
Submitted
02 Sep 2025
Quarter
2025-Q3
Submitter
t.vanhecke
Sample provenance
Supplier-supplied
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, 30 min gradient, 214 nm98.02% area≥ 92.0PASS
Total impuritiesRP-HPLC, sum of reported peaks1.98% area≤ 8.0PASS
Largest single impurityRP-HPLC — free mPEG1.31% area≤ 1.00FAIL
Identity — theoretical monoisotopic masscalculated from molecular formula7894.0000Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)7894.0087Da—NOT TESTED
Mass accuracyobserved vs theoretical+1.1ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance93.46%w/w—NOT TESTED
Target-compound contenttotal peptide content × purity91.61%w/w—NOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen2.08mg2 mg declaredNOT TESTED
Recovered target peptidegross fill × target content1.905mg2 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim95.3%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate3.75%≤ 9.0PASS
Counter-ion (acetate)anion-exchange ion chromatography2.19%≤ 12.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.60%—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 lyophilised 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 calibration5.30—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 30 min gradient17.14min17.24 ± 0.80 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.39—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²60,476—≥ 20,000PASS
Resolution to nearest impurityvs hydrolysed linker2.52—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.

01362272540875449 PEG-MGF17.14 min · 98.02 % 19.5611.5216.42 same trace · ×50 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 60,476, and skew follows the reported asymmetry factor of 1.39. 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 1.31 % impurity against a 98.02 % 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 peak17.144,764,07698.02—
2free mPEG19.5663,6701.31-2886.512
3free MGF (unconjugated)11.5213,6090.28-5007.488
4di-PEGylated species18.999,7210.20+5000.000
5hydrolysed linker16.429,2350.19+18.011
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+1128.72[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 7894.0087 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+790.4073790.40810.00088.7
9+878.1184878.11940.001050.5
8+987.7573987.75840.0011100.0
7+1128.72161128.72280.001255.9
6+1316.67391316.67540.00158.3
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 Fischer3.75
Counter-ion (acetate)ion chromatography2.19
Residual solvent + inorganic residueestimated0.60
Total peptide contentby difference93.46
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)98.598.02divergence +0.47 pp vs batch median
Total impurities (% area)not stated1.98
Largest single impurity (% area)not stated1.31
Water (%)3.03.75
Counter-ion (%)not stated2.19
Peptide content (%w/w)not stated93.46
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
Supplier-supplied
Evidentiary weight
Weaker evidence. Read with the caveat below.
Chain of custody
Supplier despatch → laboratory direct (courier, cold pack, 11 d) → assay. Submitter did not handle the vial.
Assay date
16 Aug 2025
Submitted to the index
02 Sep 2025
Laboratory
Janoshik Analytical, Ostrava, Czechia
Method basis
30 min gradient · high-resolution MS
Verification status
PARTIAL
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-2025-019136TFC-2507-M4201VendorInvestigate2025-Q396.874.30—Buyer-sourced1MARGINAL
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-2025-019142TFC-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