Bioanalysis is a sub-discipline of

analytical chemistry Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...

covering the

quantitative Quantitative may refer to: * Quantitative research, scientific investigation of quantitative properties * Quantitative analysis (disambiguation) * Quantitative verse, a metrical system in poetry * Statistics, also known as quantitative analysis ...

measurement of

xenobiotics A xenobiotic is a chemical substance found within an organism that is not naturally produced or expected to be present within the organism. It can also cover substances that are present in much higher concentrations than are usual. Natural compo ...

(drugs and their

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, ...

s, and biological molecules in unnatural locations or concentrations) and biotics (

macromolecule A macromolecule is a very large molecule important to biophysical processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. ...

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s, DNA, large molecule drugs, metabolites) in biological systems.

Modern bioanalytical chemistry

Many scientific endeavors are dependent upon accurate quantification of drugs and endogenous substances in biological samples; the focus of bioanalysis in the

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

industry is to provide a quantitative measure of the active drug and/or its metabolite(s) for the purpose of

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

, toxicokinetics,

bioequivalence Bioequivalence is a term in pharmacokinetics used to assess the expected in vivo biological equivalence of two proprietary preparations of a drug. If two products are said to be bioequivalent it means that they would be expected to be, for all ...

and exposure–response (pharmacokinetics/pharmacodynamics studies). Bioanalysis also applies to drugs used for illicit purposes,

forensic Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and crimin ...

investigations, anti-

doping Doping may refer to: * Doping, adding a dopant to something * Doping (semiconductor), intentionally introducing impurities into an extremely pure semiconductor to change its electrical properties * Aircraft dope, a lacquer that is applied to fabr ...

testing in sports, and environmental concerns. Bioanalysis was traditionally thought of in terms of measuring small molecule drugs. However, the past twenty years has seen an increase in

biopharmaceuticals A biopharmaceutical, also known as a biological medical product, or biologic, is any pharmaceutical drug product manufactured in, extracted from, or semisynthesized from biological sources. Different from totally synthesized pharmaceuticals, th ...

(e.g.

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respondi ...

and

peptides Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. ...

), which have been developed to address many of the same diseases as small molecules. These larger biomolecules have presented their own unique challenges to quantification.

History

The first studies measuring drugs in biological fluids were carried out to determine possible overdosing as part of the new science of forensic medicine/

toxicology Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating expos ...

. Initially, nonspecific assays were applied to measuring drugs in biological fluids. These were unable to discriminate between the drug and its metabolites; for example,

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat in ...

() and

sulfonamides In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. ...

(developed in the 1930s) were quantified by the use of

colorimetric Colorimetry is "the science and technology used to quantify and describe physically the human color perception". It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color ...

assays.

Antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy, ...

s were quantified by their ability to inhibit bacterial growth. The 1930s also saw the rise of pharmacokinetics, and as such the desire for more specific assays. Modern drugs are more potent, which has required more sensitive bioanalytical assays to accurately and reliably determine these drugs at lower concentrations. This has driven improvements in technology and analytical methods.

Bioanalytical techniques

Some techniques commonly used in bioanalytical studies include: *''Hyphenated techniques'' ** LC–MS (liquid chromatography–mass spectrometry) ** GC–MS (gas chromatography–mass spectrometry) **LC–DAD (liquid chromatography–diode array detection) ** CE–MS (capillary electrophoresis–mass spectrometry) *''Chromatographic methods'' **

HPLC High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify each component in a mixture. It relies on pumps to pa ...

(high performance liquid chromatography) ** GC (gas chromatography) **UPLC (ultra performance liquid chromatography) **Supercritical fluid chromatography *''

Electrophoresis Electrophoresis, from Ancient Greek ἤλεκτρον (ḗlektron, "amber") and φόρησις (phórēsis, "the act of bearing"), is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric f ...

'' *''Ligand binding assays'' **

Dual polarisation interferometry Dual-polarization interferometry (DPI) is an analytical technique that probes molecular layers adsorbed to the surface of a waveguide using the evanescent wave of a laser beam. It is used to measure the conformational change in proteins, or oth ...

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence ...

(Enzyme-linked immunosorbent assay) ** MIA (magnetic immunoassay) ** RIA (radioimmunoassay) *''

Mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is u ...

'' *''

Nuclear magnetic resonance Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a ...

'' The most frequently used techniques are: liquid chromatography coupled with tandem mass spectrometry ( LC–MS/MS) for 'small' molecules and enzyme-linked immunosorbent assay (

) for macromolecules.

Sample preparation and extraction

The bioanalyst deals with complex biological samples containing the analyte alongside a diverse range of chemicals that can have an adverse impact on the accurate and precise quantification of the analyte. As such, a wide range of techniques are applied to extract the analyte from its matrix. These include: * Protein precipitation * Liquid–liquid extraction * Solid phase extraction Bioanalytical laboratories often deal with large numbers of samples, for example resulting from clinical trials. As such, automated sample preparation methods and liquid-handling robots are commonly employed to increase efficiency and reduce costs.

Bioanalytical organisations

There are several national and international bioanalytical organisations active throughout the world. Often they are part of a bigger organisation, e.g. Bioanalytical Focus Group and Ligand Binding Assay Bioanalytical Focus Group, which are both within the American Association of Pharmaceutical Scientists (AAPS) and FABIAN, a working group of the Analytical Chemistry Section of the Royal Netherlands Chemical Society. The European Bioanalysis Forum (EBF), on the other hand, is independent of any larger society or association.

References

{{Reflist Analytical chemistry Pharmacokinetics Toxicology