How to evaluate the Quality of products

Disclaimer: the information below is based on ChemScene’s in-house scientific analysis as well as studies published by academic institutions; it serves as a guideline reference. The users should understand that the quality standard/evaluation could vary based on the testing methods, and in many cases, judgement is involved in the testing process. ChemScene will not be held responsible for any discrepancy in the case study below.

How to purchase the correct molecule?

Most of our chemical products have similar colors. However, some of the chemical products might be hard to visualize due to the small quantity or its chemical state (e.g., lyophilized solid). These products may appear as a clear thin film on bottoms and walls of the container vial. The determination of chemical structures is carried out mainly by spectroscopic methodologies, such as Infrared spectroscopy (IR), Mass Spectrometry (MS), UV-VIS spectroscopy (UV), and Nuclear Magnetic Resonance spectroscopy (NMR). NMR and MS are the most commonly used methods. Customers can find information related to chemical structure on the COA form, which is provided on our website. The NMR and MS forms are attached and shipped along with the products to our customers. Information related to specific analytical methods can also be requested from our Technical Service group.

What’s the NMR      What’s the MS
Eg. 1H NMR Spectrum of CS-1511 .

Eg. MS of CS-1511 . Eg. COA of CS-1511 .

How do you detemine the purity of products?

The purity of chemical inhibitor is the key to the success of a biological experiment. While the NMR and MS forms provide the approximate purity level, these two analyses alone are often not sufficient.


The High-performance liquid chromatography (HPLC) is a powerful method which chemists routinely use for purity evaluation. The purity information of each ChemScene's products is available online in the COA form. The HPLC information is provided along with products to our customers.

What’s the HPLC Eg. HPLC Spectrum of CS-1511 .

Chiral Purity

Chirality is a major concern in modern pharmaceutical industry due to the heightened awareness that enantiomers of a racemic drug may have different pharmacological, pharmacokinetic, and pharmacodynamic effects. Chiral HPLC is an efficient and accurate method to measure enantiomeric excess (ee.). Please review our product COA document, as well as other analysis report, for additional chiral purity information.

What’s the Chiral HPLC Eg. Chiral HPLC Spectrum of CS-1511 .

Enantiomeric excess of a mixture of enantiomers is numerically equal to its optical purity

The following relationships define the terms ee

The ee of CS-1511
ee = 99.6%-0.4% /(99.6%+0.4%) = 99.2%