Transforming an XML file into RDF with blank nodes

I am quite new in using XSLT.

I am writing an XSL transformation from an XML (metadata) document into an XML/RDF, and I am also improving the model underlying the original document. In specific, the original document describes a Person, and at some point it lists all of the person's names:

<PersonNames>
    <PersonName>
        <Surname>Doe</Surname>
        <FirstName>John</FirstName>
    </PersonName>
    <PersonName>
        <Surname>Doe</Surname>
        <FirstName>Janine</FirstName>
    </PersonName>
    <PersonName>
        <Surname>Smith</Surname>
        <FirstName>Janine</FirstName>
    </PersonName>
</PersonNames>

I don't want to connect the person's URI to each of these items separately, as by doing so it is unclear that 'Joe Smith' has never been a name of this person. I'd rather use a blank node for each name, and then link FirstName and Surname to the corresponding blank node; however, I cannot find a solution to generate a blank node's ID (which I would do inside the xsl:for-each loop that goes through all the person's names) that I can then call outside the loop and refer to.

Intuitively, I would create an id personNameID for each of these element, and then, outside the loop (and outside the subtree), I would add the corresponding triples

<rdf:Description rdf:nodeID="{$personNameID}">
    <localontology:firstName 'firstName in $personNameID'>
    <localontology:surname 'Surname in $personNameID'>
</rdf:Description>

I really don't know which functions/constructs I could use... is there someone who can help?