The blood samples were collected from the antecubital vein between 8 to 10 a.m., in a sitting position after 12 hours of fasting and avoiding of alcohol.
But that's not why I'm sharing the sentence with you. I just like the image of the hungry yet sober lab tech assuming a sitting position to collect the blood sample. I guess it just depends on how much the tech wanted a drink. But I don't think I'd like that person getting near my vein with a needle.
Now the writer's lack of facility with the English language may excuse his use of a dangling modifier. But it certainly doesn't excuse the editor of a scientific journal letting it and even more serious language problems get into print.
P.S. If you miss a spotlighted post (over there in the sidebar) that everyone is talking about, you still have three days to find it. Just scroll down in the sidebar to where it says, "these sites are well worth a visit."