chemistry

Profenofos

Profenofos is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Profenofos rather than just read about it. In short: Profenofos is an organophosphate insecticide. It is a liquid with a pale yellow to amber color and a garlic-like odor.

Key takeaways

Profenofos belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Profenofos to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Profenofos from memory before moving on to harder problems.

Reference excerpt

Profenofos is an organophosphate insecticide. It is a liquid with a pale yellow to amber color and a garlic-like odor. It was first registered in the United States in 1982. As of 2015, it was not approved in the European Union.

Uses Profenofos can be used on a variety of crops including cotton and vegetables such as maize, potato, soybean, and sugar beet. In the United States it is used exclusively on cotton and is primarily used against lepidopteran insects. Mixed with phoxim, cypermethrin, beta-cypermethrin imidacloprid and deltamethrin, profenofos can be used against Cotton MealyBug, cabbage caterpillar, Plutella xylostella and asparagus caterpillars, as well as against wheat and cabbage aphids.

Mechanism of action Like other organophosphates, the profenofos mechanism of action is via the inhibition of the acetylcholinesterase enzyme. Although it is used in the form of a racemate, the S(-) isomer is a more potent inhibitor.

Synthesis

Profenofos can be synthesized by reacting phosphorus oxychloride with sodium ethoxide and sodium 1-propanethiolate, followed by treatment with 4-bromo-2-chlorophenol.

Toxicity A 2007 World Health Organization report found no adverse effects to workers of routine exposure to profenofos and no teratogenicity or carcinogenicity. Based on a study of patients poisoned with profenofos and its close chemical relative prothiofos, the compound has been described as "of moderately severe toxicity", causing respiratory failure. Differences in chemical structure that distinguish these two compounds from more common organophosphate pesticides - namely, the presence of the S-alkyl group on the phosphorus atom where most OP compounds possess a methoxy or ethoxy group - underlie differences in their behavior as acetylcholinesterase enzyme inhibitors compared to the rest of the OP class. In one study of a patient who died of profenofos poisoning, the major metabolites of profenofos were identified as des-S-propylated profenofos, two isomers of despropylated propenofos, and desethylated propenofos. A downstream, nontoxic metabolite, 4-bromo-2-chlorophenol, has been proposed as biomarker for exposure.

Environmental effects A United States Environmental Protection Agency report identified profenofos as toxic to birds, small mammals, bees, fish, and aquatic invertebrates, noting several fish kill incidents in which profenofos exposure, primarily due to runoff, was implicated as a probable cause.

References

Illustrations

Worked examples

Example 1 — a first encounter with Profenofos

Start with the simplest possible case. Write down what Profenofos claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Profenofos before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Profenofos ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Profenofos

In research: Profenofos appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Profenofos in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Profenofos is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acetylcholinesterase inhibitors, Bromobenzene derivatives, Chlorobenzene derivatives, so understanding it makes those chapters shorter.
In everyday life: Look for Profenofos outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Profenofos in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Profenofos means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Profenofos out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Profenofos in simple terms?

Profenofos is an organophosphate insecticide. It is a liquid with a pale yellow to amber color and a garlic-like odor.

Why does Profenofos matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Profenofos?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Profenofos.