Negative of de l'

Question

I am a little confused. The lesson says that in the negative, de l' becomes d' (in front of a vowel or silent h). However, the example given: C'est de l'huile d'olive ? -Non, ce n'est pas de l'huile d'olive.

Shouldn't it then be: Ce n'est pas d'huile d'olive.

In a related doubt, are these sentences correct:

Tu as de l'argent? Non, Je n'ai plus de l'argent. (Do you have some money? No, I do not have any money.)

or should it be: Non, je n'ai plus d'argent.

Accepted Answer

That's a tricky one, but if you read the lesson again it says : 
"This rule does NOT apply to sentences using the verb être and other Verbes d'état, with which the partitive article doesn't change" 
And "est" is from the verb "être". So that is why "Ce n'est pas de l'huile d'olive" is correct. As I said, very tricky! For the second part of your question the verb is "avoir" which is not a verbe d'état, so "Je n'ai plus d'argent" is the correct choice.