AX-2026-041821

PEG-MGF · 5 mg declared · Asymchem Laboratories (Tianjin) Co., Ltd. · lot ASY-{CAT}-2379

PASSVERIFIED

Report ID: AX-2026-041821
Compound: PEG-MGF
Compound class: Growth-hormone axis peptides
Supplier: ASY — Asymchem Laboratories (Tianjin) Co., Ltd.
Batch / lot: ASY-{CAT}-2379
Declared label claim: 5mg
Laboratory: Janoshik Analytical
Assay date: 18 Jun 2026
Submitted: 09 Jul 2026
Quarter: 2026-Q2
Submitter: Contributor #W-6318
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, 30 min gradient, 214 nm	98.57	% area	≥ 92.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.43	% area	≤ 8.0	PASS
Largest single impurity	RP-HPLC — free mPEG	0.59	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	7894.0000	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	7893.9811	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-2.4	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	92.23	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	90.91	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	5.24	mg	5 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	4.764	mg	5 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	95.3	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.79	%	≤ 9.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	1.48	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.50	%	—	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	Off-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	4.36	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	17.28	min	17.24 ± 0.80 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.28	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	61,878	—	≥ 20,000	PASS
Resolution to nearest impurity	vs hydrolysed linker	2.53	—	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 61,878, and skew follows the reported asymmetry factor of 1.28. 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 0.59 % impurity against a 98.57 % 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	17.28	4,790,808	98.57	—
2	free mPEG	19.70	28,676	0.59	-2886.512
3	di-PEGylated species	19.13	23,329	0.48	+5000.000
4	free MGF (unconjugated)	11.66	12,151	0.25	-5007.488
5	hydrolysed linker	16.56	5,346	0.11	+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 7893.9811 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	790.4054	-0.0019	7.9
9+	878.1184	878.1163	-0.0021	57.5
8+	987.7573	987.7549	-0.0024	100.0
7+	1128.7216	1128.7189	-0.0027	56.9
6+	1316.6739	1316.6708	-0.0031	8.1

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.

Component	Determination	%w/w of cake
Water	Karl Fischer	5.79
Counter-ion (acetate)	ion chromatography	1.48
Residual solvent + inorganic residue	estimated	0.50
Total peptide content	by difference	92.23
Total		100.00 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.

Figure	Supplier COA	This report	Index note
Purity (% area)	98.78	98.57	divergence +0.08 pp vs batch median
Total impurities (% area)	1.22	1.43
Largest single impurity (% area)	0.44	0.59
Water (%)	4.8	5.79
Counter-ion (%)	6.6	1.48
Peptide content (%w/w)	88.0	92.23
Endotoxin (EU/mg)	0.21	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: Domestic warehouse despatch → submitter (2–8 °C, 13 d) → laboratory (courier, cold pack, 8 d) → assay.
Assay date: 18 Jun 2026
Submitted to the index: 09 Jul 2026
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

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

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 ASY-{CAT}-2379 n=2

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041822	ASY-{CAT}-2379	Janoshik	2026-Q2	98.83	6.51	—	Laboratory-retained	0	PASS

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-2026-043577	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
AX-2026-043578	SIG	SIG-2602-6794	Janoshik	2026-Q2	97.78	5.76	—	Buyer-sourced	0	PASS

Other recent ASY records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041776	TB-500	ASY-{CAT}-2167	Janoshik	2026-Q3	99.92	4.61	98.2	Buyer-sourced	0	PASS
AX-2026-041777	TB-500	ASY-{CAT}-2167	PeptideMeter	2026-Q3	99.78	4.09	92.8	Buyer-sourced	0	PASS
AX-2026-041786	Retatrutide	ASY-{CAT}-2288	VendorInvestigate	2026-Q3	98.78	6.59	—	Buyer-sourced	0	PASS
AX-2026-041782	TB-500	ASY-{CAT}-2167	Nordanalyt	2026-Q3	99.93	3.94	—	Buyer-sourced	0	PASS
AX-2026-041793	Retatrutide	ASY-{CAT}-2288	Nordanalyt	2026-Q3	98.34	6.16	104.8	Buyer-sourced	0	PASS
AX-2026-041784	Retatrutide	ASY-{CAT}-2288	PeptideMeter	2026-Q3	98.15	6.26	91.9	Buyer-sourced	0	PASS
AX-2026-041774	TB-500	ASY-{CAT}-2167	PeptideMeter	2026-Q3	99.93	4.41	96.2	Buyer-sourced	0	PASS
AX-2026-041780	TB-500	ASY-{CAT}-2167	Janoshik	2026-Q3	99.93	3.48	102.5	Buyer-sourced	1	FAIL