AssayIndex

CPC-2603-G1651

L-Carnosine · 500 mg declared · Chinese Peptide Company Co., Ltd. · manufactured 16 Mar 2026

CHARACTERISED
Lot code
CPC-2603-G1651
Supplier
CPC — Chinese Peptide Company Co., Ltd.
Compound
L-Carnosine
Compound class
Short bioregulator peptides
Declared label claim
500mg
Manufacture date
16 Mar 2026
Index quarter
2026-Q3
Independent assays
9
Laboratories involved
Nordanalyt, VendorInvestigate, Medutest, Janoshik, PeptideMeter
Provenance mix
Buyer-sourced ×2 · Supplier-supplied ×7
Section 1

Reproducibility across independent tests

Every report below is an observation of the same physical material. What they disagree about is measurement; what they agree about is the lot. The size of the disagreement is compared against what the contributing laboratories' own repeatability figures predict.

Independent assays 9
Median purity 98.24% n=9
Spread (max − min) 1.43pp n=9
Standard deviation 0.474pp n=9
97.597.998.398.899.299.7100.1This lot (CPC-2603-G1651)This lot (CPC-2603-G1651): Q1 98.05, median 98.24, Q3 98.53, n=9n=9All L-CarnosineAll L-Carnosine: Q1 98.42, median 99.07, Q3 99.83, n=29n=29 Purity (% area)
Figure 1. This lot's independent purity results against the whole L-Carnosine record set in the index. The vertical line is the index acceptance specification for the short bioregulator peptides class, 99.0 % area. A narrow box on the top row against a wide box on the bottom row is the ideal reading: it means the disagreement between lots is much larger than the disagreement within this one.
Section 2

Member reports 9

Every report the index holds on this lot. Each is a page carrying its own chromatogram, mass spectrum, mass balance, provenance and caveats.

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043281CPC-2603-G1651Nordanalyt2026-Q398.2410.17Supplier-supplied1FAIL
AX-2026-043282CPC-2603-G1651VendorInvestigate2026-Q397.6410.07Buyer-sourced1FAIL
AX-2026-043283CPC-2603-G1651Medutest2026-Q398.1010.1291.8Supplier-supplied1FAIL
AX-2026-043284CPC-2603-G1651Janoshik2026-Q399.0710.05100.3Supplier-supplied1MARGINAL
AX-2026-043285CPC-2603-G1651Janoshik2026-Q398.0510.42Supplier-supplied1FAIL
AX-2026-043286CPC-2603-G1651Janoshik2026-Q398.5310.02Supplier-supplied1FAIL
AX-2026-043287CPC-2603-G1651Janoshik2026-Q398.359.8993.2Supplier-supplied2FAIL
AX-2026-043288CPC-2603-G1651PeptideMeter2026-Q399.039.94105.1Supplier-supplied1MARGINAL
AX-2026-043289CPC-2603-G1651Janoshik2026-Q398.0110.52Buyer-sourced1FAIL
Section 3

By laboratory

Where more than one laboratory assayed this lot, the difference between them is a paired observation of their relative bias — the same material, the same time window, different instruments. Those pairs are what the index's bias estimates are built from.

LaboratoryReportsPurity results (% area)MedianGradientPublished bias (pp)Bias-adjusted
Nordanalyt198.2498.2435min+0.0298.22
VendorInvestigate197.6497.6432min-0.1197.75
Medutest198.1098.1025min+0.0898.02
Janoshik599.07, 98.05, 98.53, 98.35, 98.0198.3530min+0.0098.35
PeptideMeter199.0399.0328min-0.0599.08

This lot contributes 10 paired comparisons to the inter-lab analysis.

Section 4

The supplier's certificate for this lot

One number the supplier wrote, beside the median of the numbers other people measured on the same physical material. That comparison is only available because the index groups by lot.

FigureSupplier COAThis reportIndex note
Purity (% area)98.9198.24divergence +0.67 pp vs batch median
Total impurities (% area)1.091.76
Largest single impurity (% area)0.630.84
Water (%)not stated10.17
Counter-ion (%)not statedN/A
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)1.01not determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Impurity fingerprint

The named impurities reported across this lot's assays, with how consistently each was seen. A fingerprint is what allows two lot numbers held by different companies to be identified as one bulk.

Named impurityReported inMedian % areaRange
D-carnosine epimer9 / 90.840.39–0.99
anserine (methylcarnosine, +14 Da)9 / 90.420.11–0.50
β-alanine (−137 Da)9 / 90.290.08–0.35
free histidine (−71 Da)9 / 90.200.16–0.88
Section 7

What this rollup does not establish