http://onlinelibrary.wiley.com/doi/10.2164/jandrol.04104/full
- Semen tends to be alkaline, but to varying degrees. Studies have found the pH to be between 7.26 and 8.47.
- Semen contains many minerals and other nutritional factors including: Citrate, Sodium, Chloride, Zinc
Selenium
https://www.ncbi.nlm.nih.gov/pubmed/6500080
A mean concentration of 71.3 +/- 29.7 ng/ml of semen was found, with a range of 7 to 230 ng/ml.
There was a significant positive correlation between sperm count and semen Se
Sperm motility was maximal at semen Se levels ranging between 50 and 69 ng/ml; above and below this range, motility was decreased and the incidence of asthenospermia was high. So you can have too much of a good thing.
This study failed to find any correlations between selenium and sperm count https://www.ncbi.nlm.nih.gov/pubmed/2389993