using System;
using System.Linq;
using System.Collections.Generic;
 
public class Test
{
	public static void Main()
	{
    	List<string> myList = new List<string>()
		{
			"TNCO",
			"TNCB",
			"TNIT"
		};
		string sample = "TNSD102, WHRK301, TNIT301, YTRE234";
 
		var entries = sample.Split(new char[] {',', ' '}, StringSplitOptions.RemoveEmptyEntries);
		var firstMatch = entries.FirstOrDefault (e => myList.Any (l => e.StartsWith(l)));
		if (firstMatch == null)
			Console.WriteLine("No match!");
		else
			Console.WriteLine(firstMatch);
	}
}

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