Senior Lab Technician: GC/MS & LC/MS Data Review (On‑Site)

Viltis; Santa Rosa (CA); Hybrid; USD 28,000 - 32,000; Full time

Job summary

Viltis is seeking a Senior Laboratory Technician to support a toxicology laboratory in Santa Rosa, CA. The role focuses on processing GC/MS and LC/MS/MS data, reviewing results, and maintaining LIS entries with strict Chain of Custody controls.

The position requires a bachelor’s degree in a scientific field and the ability to work a Tuesday–Saturday schedule, 8:00 AM to 4:30 PM, in a fully on-site laboratory.

Qualifications

• Bachelor's degree in a scientific field (chemistry/biology/analytical chemistry).
• Ability to safely handle biological specimens, chemicals, equipment, and instrumentation.
• Ability to read, understand, and follow SOPs and written procedures.
• Willingness to work Tuesday through Saturday, 8:00 AM – 4:30 PM.

Responsibilities

• Read, understand, and follow SOPs for each batch.
• Identify samples and verify batch accuracy.
• Process GC/MS and LC/MS/MS data and generate reports.
• First review of analytical data per SOPs.
• Enter results into LIS for final review and certification.
• Maintain Chain of Custody documentation.
• Communicate with supervisors and address issues promptly.
• Follow safety requirements and maintain a safe lab environment.
• Work safely with specimens, chemicals, equipment, and instruments.

Skills

SOP adherence

Attention to detail

Data review

Education

Bachelor's degree in Chemistry, Analytical Chemistry, Biology, or related field

Tools

GC/MS

LC/MS/MS

LIS

Job description

Senior Laboratory Technician (Lab Tech Sr.)
Scientific Santa Rosa , California Contract Sep 17, 2026

Senior Laboratory Technician (Lab Tech Sr.)

Location: Santa Rosa, CA 95403
Schedule: Tuesday – Saturday, 8:00 AM – 4:30 PM
Hours: 40 hours per week
Pay Rate: $20.00 – $22.50/hour
Position Type: Full-Time Contract
Category: Scientific / Laboratory

Position Overview

Viltis is seeking a Senior Laboratory Technician to support our client's toxicology laboratory operations in Santa Rosa, CA.

This position is responsible for processing GC/MS and/or LC/MS/MS data following instrumental analysis for drugs of abuse. The Lab Tech Sr. will review analytical data, verify sample and batch accuracy, generate reports, enter results into the Laboratory Information System (LIS), and maintain appropriate Chain of Custody documentation.

This is an excellent opportunity for candidates with a bachelor's degree in chemistry, biology, analytical chemistry, or a related scientific discipline who are interested in gaining or expanding hands-on experience in a regulated analytical laboratory environment.

Key Responsibilities

• Read, understand, and follow established Standard Operating Procedures (SOPs).
• Correctly identify analyzed samples and verify the accuracy of sample sequences for each batch.
• Process acquired GC/MS and/or LC/MS/MS instrument data and generate appropriate reports.
• Conduct the first review of analytical data according to applicable assay SOPs.
• Transcribe or upload analytical results into the Laboratory Information System (LIS) for final review and certification.
• Maintain accurate and complete Chain of Custody batch documentation.
• Communicate effectively with supervisors and promptly escalate emerging issues or challenges.
• Follow laboratory safety requirements and maintain a safe and healthy working environment for yourself and coworkers.
• Work safely with biological specimens, chemicals, laboratory equipment, and analytical instruments.

Required Qualifications

• Bachelor's degree in Chemistry, Analytical Chemistry, Biology, or a related scientific field.
• Ability to safely work with biological specimens, chemicals, laboratory equipment, and instrumentation.
• Ability to read, understand, and consistently follow written procedures and SOPs.
• Strong attention to detail and ability to accurately document and review laboratory data.
• Ability to work the required Tuesday through Saturday, 8:00 AM – 4:30 PM schedule.

Preferred Qualifications

• Previous laboratory experience working with biological specimens.
• Experience with analytical laboratory instrumentation.
• Experience with LC/MS/MS and/or GC/MS systems or associated analytical data.
• Familiarity with laboratory information systems (LIS), regulated laboratory documentation, or Chain of Custody procedures is a plus.

Compensation & Schedule

Pay: $20.00 – $22.50 per hour
Schedule: Tuesday – Saturday
Hours: 8:00 AM – 4:30 PM
Weekly Hours: 40
Work Location: On-site in Santa Rosa, CA 95403