An interference is a substance, other than the assayed material, that can be measured by the chosen analytical method or that can prevent the assayed material from being measured. Interferences cause erroneous analytical results.
Table of Contents
What is interference effect in chemistry?
Interference: bias in the result of an analytical measurement brought about by (a) matrix mismatch between the treated test portion and the calibrators or (b) by a difference in speciation between the native analyte in the treated test portion and the analyte in the calibrators. Note 1.
What is analyte interference?
Analytical interference is defined as the effect of a substance present in the sample that alters the correct value of the result.
Which are types of interference that can happen during sample analysis?
Interferences are classified as endogenous or exogenous. Endogenous interference originates from substances present in the patient’s own specimen. Exogenous interferences are substances introduced into the patient’s specimen.
How are chemical interferences avoided?
a) A releasing agent is a substance that reacts preferentially with a chemical interference, thus preventing its interaction with the analyte. b) A protective agent is a chelating agent that prevents chemical interferences by forming stable but volatile combinations with the analyte.
How can we eliminate interference in an experiment?
If the sample components cause the multiplicative (specific) interferences, they can be eliminated by another calibration approachโthe standard addition method (SAM) [2, 3].
What are interfering substances?
Any substance, other than the ion being measured, whose presence in the sample solution affects the measured emf of a cell. Interfering substances fall into two classes: ‘electrode/electrochemical’ interferences and ‘chemical’ interferences.
What are the main interfering substances of the PT test?
For this review, we defined interference as “the effect of a substance present in the sample that alters the correct value of the result, usually expressed as concentration or activity, for an analyte.” There are four major endogenous compounds that consistently interfere with laboratory results: hemoglobin, bilirubin, …
What is ionization interference and how it can be over come?
Ionization interference is a phenomenon which shows a change in emission intensity, causing the ioniza- tion equilibrium to shift, when coexisting elements include easily ionizable elements such as Na, K, Rb, and Cs. Generally, this results in greater intensity of neutral lines and reduced intensity of ionic lines.
What causes immunoassay interference?
An important source of immunoassay interference is human endogenous antibodies, which may react with immunoassay reagents, causing either positive or negative interferences, depending on assay antibodies and architecture. These interfering antibodies are of four types: Heterophilic antibodies.
What Does interference mean on a drug test?
Abstract. Interferences relating to laboratory toxicology testing refer to results which differ from their true value and are often encountered in the setting of a drug screen compared with confirmatory testing.
How can spectral interference be prevented?
Avoidance: ICP-OES Several modern ICP instruments have the capability of avoiding the spectral interference by going to another line. Many instruments can make measurements simultaneously on several lines for 70+ elements in the same time it used to take to make a measurement on a single line/element combination.
How do releasing agents remove chemical interferences?
Releasing agent. Some chemicals generate chemical interferences in atomic absorption spectroscopy. To remove these interferences, releasing agents are used. These are cations that preferentially react with interferents and prevent chemical interferences via interactions with the analyte.
What are spectral interferences?
Spectral interferences are characterized by an overlap (either partial or direct) of the analyte of interest by an interfering element. Also the background signal for determination of an analyte signal can be interfered.
What are the interferences when using atomic absorption spectrophotometry?
SPECTRAL INTERFERENCES ๏ข Spectral interferences are caused by presence of another atomic absorption line or a molecular absorbance band close to the spectral line of element of interest. ๏ข Most of these interferences are due to molecular emission from oxides of other element is a sample.
What are the two main techniques used in analytical chemistry?
The two main methods used are wet chemistry and instrument methods. Wet chemistry, which is the classical approach to analytical chemistry, has been used for centuries. The instrument method is a fairly recent development. Both methods are still used today, but the instrument method is gaining popularity.
How do you solve analytical chemistry problems?
What are the applications of interference?
In optical testing, interference is used in testing surface quality like: flat surface, spherical surface, roughness of surface etc. Whereas in space applications include Radio astronomy, measuring light intensity, in retrieving images from the telescopes.
What is an interfering ion?
Interfering radicals are those which interfere in qualitative tests while performing salt analysis. Interfering radicals are oxalate, tartrate, fluoride, borate and phosphate and they are anionic radicals. They form complex compounds with third group reagents like ammonium chloride and ammonium hydroxide.
What are the interferences of drugs and substances in blood?
Interferences are substances such as lipids, free hemoglobin and bilirubin (also globulins and drugs) which affect the results of clinical pathologic tests, as they are being performed.
What does an increased PT mean?
The average time range for blood to clot is about 10 to 13 seconds. A number higher than that range means it takes blood longer than usual to clot. A number lower than that range means blood clots more quickly than normal.
What is interference in UV spectroscopy?
Interferences in UV- Visible spectroscopy result from several factors which can be both physical or chemical in nature. Chemical interferences result from presence of any single or group of compounds that absorb in close vicinity of the primary absorbing molecule.
What is non spectral interference?
Non-spectral interferences can be divided in reversible, that is occurring while the sample is being measured, and irreversible matrix effects, that is clogging of the nebulizer and sampling orifices or deposition on the torch or in the ion lens stack.
What is isobaric interference?
Isobaric interference is a result of equal mass isotopes of different elements present in the sample solution. Low-resolution instruments cannot distinguish between the isotopes. There are many examples in the intermediate mass regions where the second and third row transitions and the rare earths appear.
Why is an immunoassay unlikely to have a false positive result?
Interference in immunoassays leading to inaccurate results is generally unique to individuals who may fortuitously have endogenous immunoglobulin antibodies capable of interfering with those used as biological-reagents in immunoassay analysis.