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Drugs Testing Book
- Table of Contents
- Introduction
- Immunoassays and Their Screening
- An Overview Regarding the History of Immunoassays
- Basic Immunoassay Principles and Guidelines
- Variety of Immunoassays Used for Illicit Drug Testing Programs for workplaces
- Characteristics of an Immunoassay’s Performance
- Methodology Limitations
- Types and Mechanisms of Interference of Assays
- Sources of Interference
- Immunoassays and Their Application Regarding Workplace Drug Testing Programs
- Cutoff Ranges and Result Interpretation
- Selection and Troubleshooting of Immunoassays
- Summary
- Confirmation via Contemporary and Latest Techniques
- Conventional Confirmatory methods
- Gas Chromatography
- Liquid Chromatography (High Performance)
- Mass Spectrometry
- Basic Theory
- Ionization Of Electrons
- Chemical Ionization
- Full Scan Analysis
- Selected Ion Monitoring
- Quadruple Mass Spectrometer
- Quadruple ion Trap MS
- Modern Method Of Drug Confirmation
- Additional Mass Analyzers
- Time Of Flight – Mass Spectrometers
- Fticr-MS – Fourier Transform Ion Cyclotron Resonance – Mass Spectrometry
- Capillary Electrophoresis
- Summary
- Quality Assurance
- Organization Employee Assistance Programs
- Chain of Custody
- Specimen Collection
- Standard Operation Procedures
- Personnel
- Accessioning/Specimen Processing
- Security
- Internal Proficiency Testing
- External Proficiency Testing
- Inspection
- Initial and Confirmation Testing
- Equipment and Maintenance
- Laboratory Information Management System
- Records
- Specimen Validity Testing
- Quality Assurance Oversight
- Lean Six Sigma
- Summary
- Supervision of Regulated Workplace
- Historical Overview
- The Responses Of Laboratory and Regulatory Agency to the Problem
- US Federal Regulations/Criteria
- Scope of Adulterant/Substitution Products
- The HHS-Certified Laboratories Experience
- Effects of Adulterants on Analytical Tests
- Governmental Responses to the Problem
- Alternate Specimen Matrices
- Summary
- Drugs of Abuse in Hair
- Drug of Abuse in Oral Fluid
- Sweat Testing
- Amphetamines
- Opoids
- Phencyclidine
- Cocaine
- Cannabinoids
- Stability of Drugs of Abuse in Biological Fluids
- Interpretation of Workplace Drug Test Results by Medical Review Officer
- Federal Drug-Testing Programs
- Amphetamines
- Cocaine
- Marijuana
- Opiates
- Phencyclidine
- Other Drugs Tested For in Workplace Programs
- Benzodiazepines
- Barbiturates
- Methadone, Methaqualone, and Propoxyphene
- Ethyl Alcohol
- Dot-Mandated Alcohol Testing
- Specimen Validity Testing
- Additional MRO Functions Under the Federal Drug-Testing Programs
- Summary
- Laboratory Accreditation & Regulation
Basic Theory
Every MS instrument has 3 essential components: detector, mass analyzer and the ion source. Technically, the MS formulates gas phase ions, while separating the ions according to their m/z ratio. It then detects every ion and their quantity. MS can ionize compounds according to numerous ways with the EI – Electron Ionization and the CI – Chemical Ionization being the commonest ones. The EI is a conventional and commonly used method in forensic sciences.
Moreover, a number of designs can be configured and used for mass analyzers. These devices tend to measure m/z in time and space (quadruple ion trap) but their working is technically same. The ions pass through the mass analyzer via electrostatic or magnetic forces. When these forces are changed or altered, it can detect a wide range of m/z. This is relevant to the design of the analyzer and is known as the dynamic range that the instrument possesses. A dynamic range of 10 to 700 m/z is present in a conventional GC/MS analyzer.
The ability of an analyzer to divide the compounds by their integer ratio m/z is known as the Unit resolution of an analyzer. This measures the specificity of the analyzer and functions for a low resolution analyzers (less than 1000) like quadruple ion trap instruments. The unit resolution of high resolution systems such as TOF-MS and FTICR-MS is known as:
R= (m)/(∆m)
In which, m = mass of the ion and ∆m = difference in the two peaks of mass spectrum. This resolution measures the selectivity and the specificity of the instrument.
MS runs in high vacuum from 10-4 to 10-6 torr such that the ions en route to the detector, should not collide with each other. The high vacuum of the MS makes sure that the ions travel through their destined path. It also prevents contaminants such as air and water out of the MS system. Moreover, it also removes uncharged particles and prevents them from interfering.
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