An example of guanidine thiocyanate COA:
We manufacture guanidine thiocyanate ourselves and the certificate of analysis (COA) we issue tells the ground truth of our product. It is essential to be able to interpret and understand the COA. In this article, we will take batch number L20260611-1 as an example and go through its COA line by line. Below is a snapshot of the COA (the actual COA we issue is handwritten by our analyst and this snapshot is the printed version of the handwritten one):
Appearance, assay and melting point:
The appearance of guanidine thiocyanate is white crystal and the product is soluble in water and alcohol. The content or assay should be over 99.5% and the actual number is 99.69%. The high content/assay number is also supported or augmented by the melting points. The melting point range should be between 118℃ and 121℃ and the actual range is 118.8℃ ~ 120.5℃. The shorter the range, the higher the content.
Moisture, ash and ammonium:
We bound the moisture and ash content to be less than 0.3% and 0.1% respectively, which are commonly required by customers. As for the ammonium, we can remove all of it from our guanidine thiocyanate.
UV absorbance, pH, Iron and Na+:
The UV absorbance @280NM and @300NM of 3mol/L or 3M solution is required to be less than 0.2 and 0.05 respectively and the numbers we usually see are around 0.15 and 0.02. In this specific COA, they are 0.163 and 0.022. pH is required to be between 5-7 and the number came back from the testing equipment is 6.27 in this COA. We also control iron/Fe to be less than 0.1ppm and sodium to be less than 0.05%.