How to Prepare for a Lab Chemist Viva: A Complete Guide (International Standards)

A Lab Chemist Viva (Oral Examination) is a critical step in securing a role in research institutions, pharmaceutical companies, or analytical laboratories. Whether you’re a recent graduate or applying for a professional role abroad, proper preparation aligned with international standards can give you the edge.

Understand the Role and Job Description

Start by reviewing the specific job requirements:

• Type of lab (analytical, QC/QA, R&D, environmental, pharmaceutical, etc.)

• Key techniques (e.g., titration, spectroscopy, chromatography)

• Required regulations (e.g., GMP, GLP, ISO/IEC 17025)

Tip: Match your study with the laboratory standards of the country/region you're applying in, such as:

• FDA, USP (USA)

• EMA, ICH (Europe)

• ISO standards (global)

📚 Reference:

• ICH Guidelines Q2(R1): Validation of Analytical Procedures

• ISO/IEC 17025: General Requirements for the Competence of Testing and Calibration Laboratories

Master Core Practical Skills

Expect questions on:

• Standard lab procedures: Titration, pH measurement, filtration, distillation

• Instrument handling: UV-Vis, IR, HPLC, GC, AAS

• Safety and waste disposal: MSDS, fire handling, PPE usage

Example Viva Questions:

• "Explain how to calibrate a pH meter."

• "What is the retention time in HPLC and what factors affect it?"

Tip: Practice explaining instrument principles, not just steps.

📚 Reference:

• Harris, D. C. (2015). Quantitative Chemical Analysis, 9th Ed.

• Skoog, D.A., West, D.M. et al. (2017). Fundamentals of Analytical Chemistry

• Job preparation by Chemistry Job Insight

Brush Up Theoretical Knowledge

Key Areas:

• Acid-base, redox, and complexometric titrations

• Beer-Lambert Law and spectroscopic principles

• Chromatographic resolution and factors

• Buffers and solution preparation

• Read more chemistry basics

Use standard textbooks and review SOPs if you have internship experience.

Important: Learn How to Create SOPs from ISO/IEC 17025.

Study Regulatory & Documentation Practices

For international jobs, expect viva questions related to:

• Good Laboratory Practices (GLP)

• Data integrity (ALCOA+: Attributable, Legible, Contemporaneous, Original, Accurate)

• Proper documentation of results and chain of custody

📚 Reference:

• WHO: Handbook on GLP

• FDA Guidance on Data Integrity and Compliance

Know How to Handle Troubleshooting Questions

These evaluate your analytical mindset:

• "What would you do if your calibration curve isn’t linear?"

• "Why might an HPLC baseline be noisy?"

Prepare to describe root cause analysis, common errors, and corrective actions.

Be Ready for Scenario-Based Questions

Examples:

• "A colleague spills acid on their hand – what do you do?"

• "You suspect a sample mix-up – how do you handle it?"

These test your ethics, safety knowledge, and professional judgment.

Improve Communication and Confidence

• Use clear, concise language

• Practice mock viva with a mentor

• Avoid filler words and panic if you don’t know – admit and offer to learn

Tip: Use the STAR technique (Situation, Task, Action, Result) for structured responses.

Familiarise Yourself with Country-Specific Trends

For international roles:

• Understand local lab accreditation bodies

• Be aware of local chemical safety laws

• Be prepared for the cultural aspects of workplace behaviour

📚 Reference:

• Occupational Safety and Health Administration (OSHA), USA

• REACH regulation (EU chemicals policy)

Revise Final-Year or MSc Project Topics

Expect viva questions on:

• Your thesis/research objectives

• Methodology and findings

• Instruments used and challenges faced

Checklist for Viva Preparation

Preparing for a lab chemist viva aligned with international job standards means combining solid practical knowledge, theoretical grounding, and awareness of global best practices. Stay confident, stay ethical, and always be ready to learn.

Related Resources

• ICH Guidelines – Official Site

• FDA GLP Guidelines

• ISO/IEC 17025 Overview