Priming a Saison with Elderflower Cordial

hi all,
a two part question for you ...
1) i'm ready to bottle a saison (23l bottling volume at 21°C) and was thinking of using some elderflower cordial i made for priming. maths is really not my subject but i made the elderflower cordial with 1l of water for 1kg of sugar. there was only a little boil off from the cordial (boil time is short) so if i ignored this, would i be right in guessing that there is roughly .5g of sugar per 1ml of cordial and then making my sugar calculation based on that ????
2) i would also like to mix in a little citric acid to add a little tartness. what amount would you recommend to give just a hint to the finished beer?
cheers in advance !
jon

forgot to mention, once i have the correct quantity of cordial for priming, i'll work out the amount of cordial for a 330ml bottle of beer then put that in a 330ml glass of water to see how strong the flavour is ... then adjust by adding sugar if necessary

hi all,
i know that no-one replied to this question (so perhaps there's not a great deal of interest) but i thought it was worthwhile just letting you all know how it turned out.
so, i primed a single .5 litre bottle of abv 5.8% saison with 8ml of elderflower cordial, hoping to get around 3 units of co2. the beer was 21°C when bottled.
the carbonation was spot on in my opinion, however i have to say that i was not able to distinguish the taste of elderflower in the beer perhaps using the flowers in the boil or adding dried during fermentation might provide more of the elderflower flavour...
anyhoo, just thought i'd let you know.
cheers,
jon