AX-2025-020547

PEG-MGF · 5 mg declared · Shanghai Sigma-Audley New Material Technology Co., Ltd. · lot SSA-2505-U7007

MARGINALPARTIAL

Report ID: AX-2025-020547
Compound: PEG-MGF
Compound class: Growth-hormone axis peptides
Supplier: SSA — Shanghai Sigma-Audley New Material Technology Co., Ltd.
Batch / lot: SSA-2505-U7007
Declared label claim: 5mg
Laboratory: PeptideMeter
Assay date: 17 Nov 2025
Submitted: 22 Nov 2025
Quarter: 2025-Q4
Submitter: ay.lundgren
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.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 28 min gradient, 214 nm	96.52	% area	≥ 92.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	3.48	% area	≤ 8.0	PASS
Largest single impurity	RP-HPLC — di-PEGylated species	2.26	% area	≤ 1.00	FAIL
Identity — theoretical monoisotopic mass	calculated from molecular formula	7894.0000	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	7893.9574	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-5.4	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	2.96	%	≤ 9.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	1.95	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	1.01	%	—	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, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.31	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	16.30	min	16.18 ± 0.80 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	0.96	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	59,273	—	≥ 20,000	PASS
Resolution to nearest impurity	vs hydrolysed linker	2.45	—	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, 28 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 59,273, and skew follows the reported asymmetry factor of 0.96. 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 2.26 % impurity against a 96.52 % 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	PEG-MGF — main peak	16.30	4,691,171	96.52	—
2	di-PEGylated species	18.03	109,843	2.26	+5000.000
3	free MGF (unconjugated)	11.05	36,452	0.75	-5007.488
4	free mPEG	18.56	12,637	0.26	-2886.512
5	hydrolysed linker	15.63	10,207	0.21	+18.011
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 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.

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 7893.9574 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 (%)
10+	790.4073	790.4030	-0.0043	7.6
9+	878.1184	878.1137	-0.0047	55.0
8+	987.7573	987.7520	-0.0053	100.0
7+	1128.7216	1128.7155	-0.0061	49.8
6+	1316.6739	1316.6668	-0.0071	8.6

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)	95.78	96.52	divergence -0.27 pp vs batch median
Total impurities (% area)	3.77	3.48
Largest single impurity (% area)	2.21	2.26
Water (%)	1.8	2.96
Counter-ion (%)	8.3	1.95
Peptide content (%w/w)	89.3	not determined
Endotoxin (EU/mg)	0.31	not determined
Method stated on certificate	NO	—	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 (−20 °C, 24 d) → laboratory (courier, dry ice, 12 d) → assay.
Assay date: 17 Nov 2025
Submitted to the index: 22 Nov 2025
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: PARTIAL

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.
A meaningful single purity number. The conjugate's polymer is polydisperse, so the "main peak" is a distribution rather than a peak, and an area-percent figure derived from it is not comparable to a synthetic peptide purity.
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 2

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.

sodium_adduct22 Nov 2025

Adduct bookkeeping on this one is tidy. The sodium series is present at the expected intensity ratio and has not been counted as an impurity, which happens more often than it should.

sec_monomer22 Nov 2025

Polydispersity index from size exclusion is the standard descriptor for the polymer and it is absent from every certificate the index holds for this class.

Section 7

Related records

Same batch — lot SSA-2505-U7007 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020544	SSA-2505-U7007	Nordanalyt	2025-Q4	96.04	2.69	89.2	Buyer-sourced	2	MARGINAL
AX-2025-020545	SSA-2505-U7007	Janoshik	2025-Q4	96.05	1.94	92.0	Buyer-sourced	1	MARGINAL
AX-2025-020546	SSA-2505-U7007	Janoshik	2025-Q4	96.05	2.65	106.7	Buyer-sourced	1	MARGINAL
AX-2025-020548	SSA-2505-U7007	Nordanalyt	2025-Q4	95.57	3.10	95.9	Buyer-sourced	1	MARGINAL
AX-2025-020549	SSA-2505-U7007	PeptideMeter	2025-Q4	95.96	2.61	107.1	Buyer-sourced	1	MARGINAL
AX-2025-020550	SSA-2505-U7007	Janoshik	2025-Q4	96.30	3.03	93.9	Buyer-sourced	1	MARGINAL
AX-2025-020551	SSA-2505-U7007	Janoshik	2025-Q4	95.93	3.16	97.8	Laboratory-retained	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent PEG-MGF records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041821	ASY	ASY-{CAT}-2379	Janoshik	2026-Q2	98.57	5.79	95.3	Buyer-sourced	0	PASS
AX-2026-043577	SIG	SIG-2602-6794	Kestrel	2026-Q2	97.66	6.08	—	Buyer-sourced	0	PASS
AX-2026-043570	SIG	SIG-2602-6794	PeptideMeter	2026-Q2	97.76	5.45	104.2	Buyer-sourced	0	PASS
AX-2026-043569	SIG	SIG-2602-6794	PeptideMeter	2026-Q2	97.52	5.36	—	Laboratory-retained	0	PASS
AX-2026-043573	SIG	SIG-2602-6794	Janoshik	2026-Q2	98.58	4.79	104.2	Buyer-sourced	0	PASS
AX-2026-041822	ASY	ASY-{CAT}-2379	Janoshik	2026-Q2	98.83	6.51	—	Laboratory-retained	0	PASS
AX-2026-043574	SIG	SIG-2602-6794	Kestrel	2026-Q2	98.04	5.98	88.6	Buyer-sourced	1	MARGINAL
AX-2026-043576	SIG	SIG-2602-6794	Nordanalyt	2026-Q2	97.61	5.56	—	Buyer-sourced	0	PASS

Other recent SSA records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043135	BPC-157	SSA-2601-N6863	Nordanalyt	2026-Q2	98.16	4.66	92.8	Buyer-sourced	1	MARGINAL
AX-2026-043160	GHK-Cu	SSA-2604-V7731	Janoshik	2026-Q2	98.01	4.02	91.8	Buyer-sourced	0	PASS
AX-2026-043157	GHK-Cu	SSA-2604-V7731	Medutest	2026-Q2	99.19	5.14	—	Supplier-supplied	0	PASS
AX-2026-043141	BPC-157	SSA-2601-N6863	Janoshik	2026-Q2	98.06	4.06	94.6	Buyer-sourced	1	MARGINAL
AX-2026-043154	GHK-Cu	SSA-2604-V7731	PeptideMeter	2026-Q2	97.82	4.82	101.6	Buyer-sourced	0	PASS
AX-2026-043137	BPC-157	SSA-2601-N6863	PeptideMeter	2026-Q2	98.17	4.14	—	Buyer-sourced	1	MARGINAL
AX-2026-043162	GHK-Cu	SSA-2604-V7731	Janoshik	2026-Q2	98.50	4.36	—	Supplier-supplied	0	PASS
AX-2026-043134	BPC-157	SSA-2601-N6863	Medutest	2026-Q2	97.89	4.01	—	Buyer-sourced	1	FAIL