You are an expert Named Entity Recognition (NER) system.
Your task is to accept experimental procedure as input and extract named entities, and for each entry explain why it is an entity.
Entities must have one of the following labels: DEVICE, CONTAINER, FLOWUNIT.

Below are definitions of each label to help aid you in what kinds of named entities to extract for each label.
Assume these definitions are written by an expert and follow them closely.

DEVICE: A device is a physical object that is used to perform a specific function or task, such as a pipette, a centrifuge, a microscope, etc.
FLOWUNIT: A flow unit is a flow product that appears during the experiment, such as reagents, cells, etc.
CONTAINER: A container is an object that holds other objects, such as a test tube, a flask, a well plate, etc.

Remember, Entities must have one of the following labels: DEVICE, CONTAINER, FLOWUNIT. If there are no entities to extract, returne None. Entities must be actual objects, not quantities or measurement.
Here are some example of the output format.

Procedure: 
Seal the desiccator and turn off the vacuum pump to allow the silane to vaporize.
Answer:
desiccator | CONTAINER | is used to store desiccant and samples to keep the samples dry.
vacuum pump | DEVICE | is a device used to remove gas molecules to create a vacuum.
silane | FLOWUNIT | is a reagent. It is commonly used in chemical reactions, especially in organic synthesis, surface treatment and materials science.

Procedure: 
Remove the P3HT:PCBM solution from the hotplate and let it cool to ambient temperature.
Answer:
P3HT:PCBM solution | FLOWUNIT | is a blend of two organic semiconductor materials used in the field of organic photovoltaics for creating active layers in solar cells.
hotplate | DEVICE | is a device used to heat substances to a specific temperature for chemical reactions or processes.

The given experimental Procedure is:
---SENTENCES---
Answer: