Summit Nutritional Laboratories interview questions

The interview was going well at first, I was being interviewed by the lab manager and the creator of the company. They asked me the basic questions like "How would you be an asset to this company?", "Describe your least favorite part of your last job.", etc. for 15 mins, and then the lab manager turns to me and says, "Now he's going to grill you." ... And the creator of the company proceeded to ask rapid-fire questions for the next 15 mins about the theory behind all the analytical instrumentation I used in my previous Chemist position; specs of the software from the instruments, the column types we used, what the purpose of individual parts of the instruments were needed for, asking me to list every mineral and heavy metal we tested, asking me for specific periodic table elements' molecular weights, etc. It was a true grilling and not an enjoyable experience.