Role Overview We are seeking a Principal Scientist to act as a subject matter expert across LC-MS/MS bioanalytical programmes supporting PK and PD studies. This role provides scientific leadership across multiple studies, focusing on complex problem-solving, assay strategy, and client engagement. Key Responsibilities Provide scientific leadership and SME support across LC-MS/MS studies Lead troubleshooting of complex analytical challenges, including matrix effects, sensitivity limitations, and assay robustness Advise on method development, optimisation, and validation strategies Support study teams in resolving technical issues and ensuring consistent assay performance Contribute to client interactions, including scientific discussions, data interpretation, and method justification Support proposals, bid defences, and scientific strategy discussions Mentor and support development of laboratory scientists Technical Expertise Strong knowledge of LC-MS/MS theory, including triple quadrupole and HRMS systems Experience with sample preparation techniques such as SPE, LLE, protein precipitation, and hybrid workflows Deep understanding of quantitative bioanalysis, including calibration strategies, selectivity, and matrix effects Experience with Complex Modalities Peptides and proteins Oligonucleotides Antibody-drug conjugates and related conjugates Regulatory and Client Experience Extensive experience working under GLP and GCP Strong understanding of regulatory guidance (FDA, EMA, MHRA, M10) Experience supporting audits and regulatory inspections Proven ability to lead scientific discussions with clients and defend analytical approaches and data Ability to communicate complex technical issues clearly and challenge client assumptions where appropriate Qualifications and Experience PhD in Analytical Chemistry or related field, or MSc with significant industry experience 10 to 15 or more years of LC-MS/MS bioanalysis experience Demonstrated expertise in method development, validation, and advanced troubleshooting