The present invention provides an industrially available method for efficiently producing high-purity S–6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in solid-liquid separability from an S–6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester, and also provides products obtained by the method. In one example embodiment, this is accomplished by computing source PE IP and source PE interface from each flow record received at a destination PE router to identify an associated source VPN site. The at least one cooling plate is traversed by a flow of fluid and is formed from two metal layers that are connected to one another. The screed determines the thickness of the material on the subgrade as it is manipulated by adjusting the height of the tow point such that the top surface of the material follows a reference surface. A pad is pivotally connected to the distal end of the upper arm. Access to the normal memory elements is disabled based on the programmed redundancy addresses.