var xd = new XmlDocument();
xd.LoadXml(Properties.Resources.Soap);
foreach (XmlNode item in xd.SelectNodes(@"//*|//@*"))
{
  var xpn = item.CreateNavigator();
  xpn.MoveToFollowing(item.NodeType==XmlNodeType.Element ? XPathNodeType.Element : XPathNodeType.Attribute);
  var nsDic = xpn.GetNamespacesInScope(XmlNamespaceScope.ExcludeXml);
  if (nsDic==null) continue;
  nsDic.ToList().ForEach(kvp=>
    Console.WriteLine("{0} {1}: prefix: {2}; namespasce: {3}",
      item.NodeType,
      item.LocalName,
      kvp.Key,
      kvp.Value));
}