In my undergraduate research I needed to separate volatile organic compounds from a complex mixture.

Select an appropriate separation technique that provides high resolution for volatile analytes.

I chose gas chromatography because the compounds had low boiling points and were thermally stable, allowing rapid separation on a non‑polar column with a temperature program.

The GC run resolved all target peaks within 5 minutes, enabling accurate quantification and saving instrument time compared to HPLC.

During a formulation project I needed a buffer at pH 7.4 for a protein assay.

Calculate the ratio of conjugate base to acid to achieve the target pH.

I applied the Henderson‑Hasselbalch equation, pH = pKa + log([A⁻]/[HA]), using the pKa of phosphate (7.2) to determine a 1.58:1 ratio, then mixed the appropriate amounts of Na₂HPO₄ and NaH₂PO₄.

The resulting buffer maintained pH 7.4 ±0.05 over 24 hours, ensuring assay reproducibility.

After synthesizing a new ester in the organic lab, I needed to confirm its purity before scale‑up.

Use ¹H NMR to assess impurity levels and verify structural integrity.

I recorded a high‑resolution ¹H NMR spectrum, integrated peaks corresponding to the ester’s methylene and methyl groups, and compared them to the expected pattern. Any extraneous peaks were quantified by integration relative to an internal standard.

The spectrum showed >98 % purity with only trace solvent peaks, allowing me to proceed to the next reaction step confidently.

In a polymer chemistry internship I was tasked with reporting the DP of a poly(ethylene terephthalate) batch.

Convert the measured Mn to DP using the monomer repeat unit weight.

I divided the Mn (45,000 g mol⁻¹) by the molecular weight of the repeat unit (192 g mol⁻¹), yielding a DP of ~235.

The calculated DP matched the target specification, confirming successful polymerization and enabling downstream processing decisions.

At my previous university lab I was involved in updating the CHP after a new reagent was introduced.

Identify and document essential CHP elements to ensure regulatory compliance and worker safety.

I ensured the plan included a chemical inventory, standard operating procedures, exposure limits, personal protective equipment requirements, waste disposal protocols, and emergency response procedures.

The revised CHP passed the institutional safety audit with no citations, and lab members reported increased confidence in handling hazardous chemicals.

Our organic synthesis lab experienced frequent fume hood alarms due to solvent vapors.

Implement controls to minimize inhalation exposure.

I applied the hierarchy: first, substituted a high‑volatility solvent with a less volatile alternative (engineering control). When substitution wasn’t feasible, I upgraded the fume hood airflow and introduced local exhaust ventilation (engineering). I also reinforced PPE usage and provided training (administrative and PPE).

Airborne solvent concentrations dropped by 70 %, and the lab passed the annual industrial hygiene inspection without violations.

During a project I generated a mixed waste stream of dichloromethane and copper sulfate residues.

Develop a disposal protocol that meets hazardous waste regulations.

I first segregated the waste by phase separation, extracting the organic layer for collection as hazardous organic waste. The aqueous phase containing copper was neutralized, precipitated, and filtered. The solid copper salt was then sent to a licensed metal recycling facility, while the aqueous filtrate was treated to meet discharge limits before disposal.

All waste was disposed of in compliance with EPA RCRA guidelines, and the audit report showed zero non‑compliance findings.

Before initiating a novel organophosphorus synthesis, my supervisor required a formal risk assessment.

Identify hazards, evaluate risks, and propose mitigation measures.

I listed each reagent’s toxicity, consulted SDSs, evaluated exposure routes, and used a risk matrix to score severity and likelihood. Controls included using a certified fume hood, wearing double gloves, implementing spill kits, and scheduling a safety briefing. I documented the assessment in the lab’s risk register.

The experiment proceeded without incident, and the risk assessment was cited as a model during the department’s safety review.

In my graduate research a Suzuki coupling yielded only starting material after 24 hours.

Identify the cause of failure and recover the project timeline.

I reviewed the reaction parameters, confirmed the palladium catalyst freshness, checked the base’s moisture content, and ran a small-scale test varying the solvent polarity. I discovered that residual water in the base quenched the catalyst. Replacing the base with a freshly dried version and adding molecular sieves restored activity.

The optimized reaction gave 85 % isolated yield, allowing me to meet the conference abstract deadline.

As a post‑doc I needed to ensure my project aligned with emerging green chemistry practices.

Develop a routine for continuous learning and knowledge sharing.

I subscribed to key journals (JACS, Green Chemistry), set up RSS alerts for relevant keywords, attended monthly webinars, and presented summaries at our lab meetings. I also participated in a professional society’s special interest group on sustainable synthesis.

My incorporation of a solvent‑free protocol reduced waste by 40 % and was later highlighted in the department’s annual report.

During a community outreach event I was asked to explain why plastic recycling is challenging.

Translate polymer degradation concepts into layperson terms.

I used analogies comparing polymer chains to spaghetti strands that can be cut but not easily re‑joined. I illustrated the difference between thermoplastic and thermoset plastics with simple visuals and highlighted the role of additives that hinder recycling. I kept the talk under ten minutes and encouraged questions.

Attendees reported a clear understanding, and the local school incorporated the presentation into its science curriculum.

Our analytical chemistry lab lacked a standardized SOP for calibrating HPLC systems, leading to inconsistent results.

Develop a robust, reproducible SOP and train staff.

I benchmarked industry best practices, drafted a step‑by‑step protocol including system suitability tests, calibration frequency, and documentation templates. I piloted the SOP with three analysts, collected feedback, and refined the document. Finally, I conducted a training workshop and instituted a quarterly audit schedule.

Calibration variance dropped from 12 % to 2 %, and the lab achieved ISO 17025 compliance during the next external audit.