Well probably the very nature of latinum not being able to be replicated is what makes it valuable. If it was easily reproduced, it wouldn't make a viable currency to say the least.
It's implied throughout DS9 you can't replicate it, but never flat out said. If you could replicate it that regurgitated latinum that Quark got so excited about wouldn't be anything important for example. The novels flat out state it can't be.
I always thought Quark's biting the latinum was testing either it's density much like we did with gold(maybe gold with latinum in it has it's own unique density?) or the sound his teeth make against it(since Quark says GPL makes a unique sound).