Notification of Shodex Column CoA Misdescriptions and Issue of Amended CoA

Resonac Corporation
Functional Chemical Division

Dear valued customers,

Thank you for purchasing and using Shodex products.

We notify that it has been revealed that some Shodex products manufactured in the past have errors in the inspection items “Plate Count” and "Asymmetry Factor (Fas)" provided in the Certificate of Analysis (CoA). The cause was that when inspection analysis software was updated, wrong Plate Count and Fas calculation formulae were applied and the mistakes were not realized.

The result of recalculation confirmed that provided Plate Count and Fas values were within the product standard specifications. Regardless, we sincerely apologize for causing this error that may have led to lose your trust in our products.

We will issue amended CoAs with correct values for the corresponding product that you purchased (please see below). Please kindly follow the “Request Form” to fill in the required items including the product name and serial number. Then, amended CoA PDF file will be sent to the registered e-mail address.

Corresponding Period

2017 – 2021

To Request the Replacement

Please fill-in the required items in "Request Form for Shodex CoA Replacement".

Corresponding Products

Please click the product name to check the serial number.

Note:The serial number follows "No." on the product tag attached to the product body, "S/N" on the product outer box label, or "Column number" on the Certificate of Analysis. Please check the 8-digit characters.

About Plate Count Calculation Formulae

There are multiple methods for calculating the number of theoretical plates (N), i.e., plate count. Typical examples are the "half width method" used by the Japanese Pharmacopoeia (JP) and the "tangent method" used by the United States Pharmacopeia (USP), each of which is defined as follows.

For Shodex products, as described on the Shodex homepage and product instruction manuals, “half width method” should had been adopted, however “tangent method” had been mistakenly applied during the stated period.

About Peak Symetry Calculation Formulae

Concerning peak symmetry, there are two major index. One is "Asymmetry Factor (Fas)" which is recommended by ASTM International, the world's largest organization of standards. Another one is "Symmetry Factor (S)" which is recommended by the United States Pharmacopeia. They are defined as follows.

For Shodex products, as described on the Shodex homepage and product instruction manuals, “Asymmetry Factor (Fas)” should had been adopted, however “Symmetry Factor (S)” had been mistakenly applied during the stated period.

Measures to Prevent Recurrence

The Plate Count and Fas formula in the analysis software have been revised and corrected to the ones that should had been applied.
Finally, we will endeavor to strengthen quality control furthermore in order to provide you reliable products that satisfy your analytical needs.

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