The COA of N acetyl cysteine: Item Limit Result Identification Infraredabsorption Conforms Specificrotation[a]D25° +21° +27° +24.0° PH 2.0 2.8 2.39 Lossondrying ≤1.0% 0.5% Residueonignition ≤0.5% 0.26% Heavymetals ≤0.001% <0.001% Organicvolatileimpurities Meetstherequirements Conforms Assay 98.0 102.0% 99.6% Conclusion:ThetestresultoftheabovementionedproductmeetsUSP32standard. Package: Uses: cure bronchitis, used in the cure of liver diseases, antioxidant and antidote. Welcome to your esteemed inquiry.