Checking temporal dependency

Hi guys, this is my problem: I have performed some experimental tests (tomographies) on 40 samples. These samples are made by four different manufacturers (each manufacturer sent me 10 samples). I have performed an ANOVA test to check if the manufacturer is a significant factor. Then I have checked the normality assumption of the standardized residuals (SRES) with a Anderson-Darling’s test. Now I want to check if there is some dependency among the SRES. To do so I usually use the autocorrelation function in Minitab (Stat – Time Series – Autocorrelation). But now the problem is that I have performed the experimental tests with a set of 4 samples (so 10 experimental tests in total). How can I check the dependency?
Best regards