Transmigrated into Conan, his ability is Rhodes Island

"A catalyst?" The section chief frowned and asked, "I remember it refers to a substance that accelerates a chemical reaction but isn't consumed in the process?"

Ida Kou, having shaken off his earlier confusion, began to give his colleagues a brief explanation of what a catalyst was, as if he had received a detailed explanation from the forensic pathologist. "You can think of it as a 'helper,' which helps the reaction proceed faster, but in the end, it remains intact."

At this point, a police officer interrupted curiously, asking, "So what exactly is the catalyst for this reaction?"

Ida Kou was a little troubled. He explained, "Those forensic professors said that it would take several weeks or even months to determine its composition and structure through a series of complex tests, including mass spectrometry, nuclear magnetic resonance imaging, and infrared spectroscopy..."

As the police officers remained silent, Akihara Kazumitsu coughed softly, drawing everyone's attention.

"I think you can go and arrest the people associated with that pharmaceutical company."

"Why do you say that?" After a brief silence, the section chief asked seriously.

“I think they probably weren’t without a 24-hour hotline, but rather they were preparing to run away when they saw it was the police calling.” Akihara Kazumitsu’s eyes darted around, as if searching for something.

"So, you're finally ready to reveal your reasoning now?" Kenji Hagiwara understood the deeper meaning behind the other person's words.

Akihara Kazumitsu, having failed to find what he was looking for, regretfully withdrew his gaze and nodded. "Yes, the evidence is almost there."

"What were you looking for just now?" Kenji Hagiwara asked, swerving off-topic again.

"Find an electronic whiteboard... never mind what I said." Akihara Kazumitsu looked at Date Wataru and began to ask him for help with practiced ease: "You can have the forensic department prioritize checking if it was a catalyst used in the synthesis of triethylaluminum."

Ida Kou subconsciously nodded in agreement.

Under the watchful eyes of the police officers, Akihara continued unhurriedly, "First, let me state my conclusion: there are many irrelevant and misleading factors in this case, including the location of the crime and the delayed smoke extinguisher... In other words, the method used in this case determines that he could have succeeded no matter when or where."

He put down the materials in his hand, his expression becoming serious: "There are only three key points in this case: aluminum hydroxide, ethanol, and this high-performance catalyst."

"I'm sure everyone knows about the process by which ethanol is broken down in the human body, right?"

Akihara Kazumitsu didn't forget to interact with the others, but when he looked around, he found that no one was responding to him.

He had no choice but to explain further: "...Well, okay, let me explain in detail...Ethanol enters the victim's bloodstream through his respiratory tract, then is sent to the liver, where it is oxidized into acetaldehyde by alcohol dehydrogenase ADH."

As Akihara Kazumitsu spoke, he would occasionally glance at the wall of the underground parking lot, his hand itching to write or draw on it for them.

"Here's the interesting part. Acetaldehyde decomposes into ethylene and oxygen under the action of a catalyst... This reaction is very weak, but it's sufficient for this method."

"Next comes the key to the whole reaction, which is still this high-performance catalyst, which will promote the combination of aluminum hydroxide and ethylene, ultimately forming triethylaluminum—a Class 1 hazardous substance that will ignite when it comes into contact with oxygen and explode when it comes into contact with water."

As Akihara finished speaking, he looked at everyone like a real teacher, his eyes piercing and full of expectation as he looked at each "student," waiting for their response.

Matsuda Jinpei snapped out of his daze. "Even so, there can't possibly be enough oxygen for a fire to start inside a person's liver, right?"

Akihara Kazumitsu smiled encouragingly. "As I just mentioned, oxygen is produced during the decomposition of acetaldehyde. Even if that's not the case, there's still plenty of water to react with triethylaluminum; at worst, it won't burn, but rather blow the liver apart..."

Understand the old black snake, become the old black snake. It feels really good to be a teacher.

"As for why I suspect that pharmaceutical company, firstly, triethylaluminum is a dangerous substance, and its catalyst is naturally strictly controlled. Ordinary people cannot obtain such a thing."

"Secondly, the best way to get the victim to take the catalyst without them knowing is to mix it with other drugs during the drug trial, for example, by disguising it as a capsule and having the victim take it."

"Finally, in addition to the catalyst, another key reactant, aluminum hydroxide, also comes from this company."

Akihara Kazumitsu raised his hand as if to tap the blackboard, but there was no blackboard for him to tap on, so he snapped his fingers, drawing the attention of everyone who was deep in thought back to him.

"Alright, let's go over this case again."

“Yesterday, the victim tried a new type of stomach acid suppressant drug, which contained a capsule whose contents were a catalyst. Over the next two to four hours, the capsule was in his stomach, where stomach acid gradually dissolved its outer shell, eventually releasing the catalyst inside for further transport.”

"When he was unaware of what was happening and was about to 'finish get off work' and go home, someone may have said something like, 'Buy some disinfectant alcohol to kill germs and prevent bringing germs home.'"

"Of course, this person is my assumption and fiction. In reality, if the murderer really wanted to harm him, he could have replaced the windshield washer fluid in his car with one containing ethanol. That way, when the victim sprayed the windshield washer fluid to wipe the windows, the highly volatile ethanol would also enter the car through the external air circulation system and be inhaled by the victim, achieving the same effect."

"In any case, the victim still went to buy disinfectant alcohol. However, the pharmacy he went to happened to be out of stock and only had anhydrous ethanol, so he decided to mix tap water with anhydrous ethanol to use as disinfectant alcohol."

“He wasn’t a member of this supermarket, so he parked his car in a nearby parking lot. When he got out of the car, he filled a mineral water bottle with some anhydrous ethanol and carried it in his hand, intending to go to the supermarket to get some tap water to disinfect it before going home.”

"After getting the water, in order not to affect others, he decided to disinfect himself in the underground parking lot. He sat on the metal triangular stool, put the bag he was carrying aside, and then used diluted ethanol."

As Akihara Kazumitsu finished speaking, he looked at the charred marks behind the pillar.

"The final result was just as I just described: the victim's liver caught fire, and he eventually collapsed here."