Hi. Contamination usually leads to a lower than expected 260/230.

The nucleic acid is detected at 260 and most contaminants at around 230.

How are you quantifying your sample and what blank are you using?

Since that ratio is very high, you may have contamination with the compounds used for RNA isolation, probably organic compounds, like Trizol (phenol) or guanidine salts. I think you should either separate phases better and avoid pippeting the aquous phase ultil the end. Good luck.

A high RNA 260/230 ratio with good 260/280 ratios and high concentrations suggests relatively pure RNA but may indicate contamination by organic solvents, guanidine salts, or carbohydrates.

To improve the protocol, optimize purification steps, increase ethanol washes, use RNase-free materials, and consider a DNase treatment to remove residual DNA.