Just for fun, since all the better ones are already taken: eliminate the whitespace and do the split in one shot:

@x = map {tr/ //d;$_} split /(?<=[[:alpha:]])[\s,]+(?=\d)|(?<=\d)[\s,]
++(?=[[:alpha:]])/, $string;
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First, split the string whereever there is a letter followed by a space or comma followed by a digit or the other way round, then eliminate all remaining spaces. The array @x will contain the strings an digits.

pike