If splash racking does not resolve the issue, the next level resolution for H2S is redulees or copper sulfate. I haven't had much luck with redulees (active ingredient is copper), so I go right to the copper solution. The copper will react with the H2S and precipitate out. The important thing is to only use the minimal amount of copper sulfate necessary to rid your wine of H2S. If you add more than that, the copper will stay in solution, which you do not want. Finding the right amount is determined through bench trials on smaller samples.