The wave of suspected attacks has affected thousands of schoolgirls and provoked public anger.
One woman had survived Sararat's poisoning attempt and is now being questioned.
Nasyrova had also drugged, and robbed men while working as a dominatrix and is accused of murdering her neighbor in Russia.
Poison gas attacks on schoolgirls in Iran have shocked the world for months, from the first reports in November, at the height of the protests against the regime.
If the illness of Iranian schoolgirls is not caused by “mass sociogenic illness,” then it raises a fundamental question about the underlying reason for these incidents.
Sources have provided The Media Line with a true picture of the extent of the incidents, including the names of many of the schools singled out for attack
The poisonings began in November in the holy Shi'ite Muslim city of Qom and spread to 25 of Iran's 31 provinces, prompting some parents to take children out of school and protest.
Iranian pro-regime media are afraid that the regime will be blamed, so they have deployed a number of theories about what happened in order to distract attention from the events.
The so-far unexplained poison attacks at more than 30 schools in at least four cities started in November in Iran's Shi'ite Muslim holy city of Qom.
Iranians chanted "death to the child-killing government" after eight schools reported poisonings in one day.