A Brief Tour of the Chemistry Section of WVDL
The chemists at WVDL have the use of sophisticated instrumentation. These types of equipment are considered the norm in a diagnostic chemistry lab and are invaluable workhorses. Here is a very brief introduction of some of our more important instruments:
HPLC: High Performance Liquid Chromatograph
Liquid chromatography is used to separate non-volatile (not easily vaporized) analytes from one another by using high-pressure pumps to push the analyte liquid through a packed column in a solvent (mobile phase). The analytes in the sample react differently to the column packing, causing each to spend a different amount of time in the column before being pushed out by the mobile phase (retention time). The order in which the analytes are detected, and the retention times at which they are detected, help us to identify the various chemical species in the analyte.
Our HPLC is equipped with a UV detector, and is primary used for Vitamin A and Vitamin E analyses of serum and livers.
HPLC/MS: High Performance Liquid Chromatograph-Mass Spectrometer
This instrument is an HPLC fitted with a mass spectrometer detector. This instrument takes separated chemical species, fragments them, then precisely separates and quantifies them by mass. LC/MS is the workhorse of non-volatile drug and pesticide analysis.
We use our LC/MS to analyze the following: taurine, anticoagulants (rodenticides), ionophores, and non-volatile pesticides.
HPIC: High Performance Ion Chromatograph
Much like HPLC, the HPIC consists of pumps, a packed column, and a detector. In this case, the column separates anions (or cations) based on charge via ion-exchange reactions.
We use our HPIC for anion analysis: primarily nitrites, nitrates and sulfates.
GC/MS: Gas Chromatograph-Mass Spectrometer
Gas chromatography works similarly to liquid chromatography, except everything is in the gaseous phase. The organic sample is volatilized-vaporized and pushed through a long, hollow-core column (about 30 meters) by an inert gas (usually helium). The order and time at which the analyte species are eluted from the column helps to identify them. Our GC is fitted with a MS detector, which quantifies the mass of each analyte as it elutes from the column. We have access to a large electronic library of chemicals (200,000+ compounds) within the software which can match the precisely measured mass spectra to those in the library, thus identifying the analytes.
Our GC/MS is used for detection of chemicals which can be volatilized within the drug and pesticide groups, and also for ethylene glycol analyses.
ICP-MS: Inductively-Coupled Plasma Mass Spectrometer
This instrument ionizes liquid samples (dilute fluids or digested tissues) via very hot Argon plasma (~10,000o Kelvin). The ions are then separated by mass and counted by the pulse count detector (for trace elements) or the analogue detector (for more concentrated macro elements). By separating and counting the number of atoms at each mass of interest, we can determine the concentration of each element of interest.
We use our ICP-MS for element-mineral panel analyses, as well as individual metal-mineral analyses if requested.
And there you have it: a broad overview of what some of these instruments do, and how we use them here in the Chemistry section of WVDL. These pieces of equipment require considerable care and maintenance, both preventative and day-to-day. We keep them working their best and optimized in order to provide our clients with accurate results and in order to keep them running for years to come.