var str = "My name @is ,Wan.;'; Wan";
var charsToRemove = new string[] { "@", ",", ".", ";", "'" };
foreach (var c in charsToRemove)
{
str = str.Replace(c, string.Empty);
}
But I may suggest another approach if you want to remove all non letter characters
var str = "My name @is ,Wan.;'; Wan";
str = new string((from c in str
where char.IsWhiteSpace(c) || char.IsLetterOrDigit(c)
select c
).ToArray());