Chemical Analysis

Consumer Products, Advanced Materials, Medical Devices, Adhesives

MAS provides several options for destructive and non-destructive testing for a number of compounds including phthalates, flame retardants, fungicides, BPA, lead, cadmium, chromium, mercury, other heavy metals, and polycyclic aromatic hydrocarbons. We are approved by the U.S. Consumer Product Safety Commission (CPSC) as a certified laboratory to assist manufacturers, importers, distributors and retailers to meet Consumer Products Safety Information Act (CPSIA) obligations. We analyze products, dust, wipes, and air samples from a variety of consumer products, including children’s toys, for these components.

We characterize properties of solids, liquids, powders, adhesives and compare those properties to libraries, standards, or other samples. In many cases, samples can be compared to each other, to standards, and to libraries and are also assessed for comparison to known compound signatures. They can be used for presence/absence determinations as well. Several Chemical Analysis Techniques MAS utilizes are described here.

Inductively Coupled Plasma/Optical Emissions Spectroscopy

ICP analysis is a powerful method that is used to detect and measure elements and trace metals in samples. ICP-OES is used to quantify metals in materials such as solids, paints, wipes, liquids, and air filters. In the ICP, the argon gas passes through the torch and is charged with an electromagnetic coil. The argon gas is lit which causes the gas to become ionized. Electrons collide with the argon atoms causing argon electrons to be released. The released electrons are accelerated by the electromagnetic unit which causes the magnetic field to shift. This continues until the plasma is generated.

Samples are introduced into the plasma via spray chamber where larger droplets are removed from the sample optimizing stability and efficiency.

Many chemical elements are ionized and evaluated using the ICP. ICP-OES can also be used as a screening tool. ppb level quantification of metals, including heavy metals such as Pb, Cd, Cr, Hg, and Sn can be achieved. ICP-OES is synonymous with ICP/AES (Inductively Coupled Plasma/Analytical Emission Spectroscopy).

Gas Chromatography with Mass Spectrometry - Pyrolysis

When a sample is analyzed by pyrolysis, it is placed in a quartz tube and heated in the GC between 80 to 1000 Celsius. The sample is heated to thermal decomposition allowing the sample break down into smaller molecules by gas chromatography and then detected using mass spectrometry.

Pyrolysis is useful to identify components in materials even at trace levels. Pyrolysis requires a small amount of sample and very little preparation, so it is ideal for materials that are difficult to analyze using traditional GC-MS methods. Pyrolysis GC/MS can also serve as a screening tool programmable from 300 to 700 degrees with various hold times.

Headspace Gas Chromatography with Mass Spectrometry

The addition of Headspace to GC/MS allows for volatile and semi-volatile organics in various matrices to be analyzed by the GC/MS. Solids or liquids, adhesives, powders, and samples that do not dissolve easily are examples of ideal samples for Headspace GC/MS analysis.

Ion Chromatography

The IC uses ion chromatography which is the separation and quantitative analysis of ions (anions and cations) using ion exchange. This is a process that separates the mixture of ions that takes place on the IC’s column. The ions in the sample are injected into the instrument and carried through the system by a mobile phase (eluent), and ion exchange occurs on the column (stationary phase). The ions separate based on their charge and the mobile phase (eluent) used in the analysis.

This solution of separated ions and eluent is passed through a detector where the conductivity of the mobile phase is measured to determine the quantity of ions. Each ion exits the column within a specific time frame (retention time) and is measured by plotting concentration vs time. The IC technique is useful for presence/absence of anions/cations, sulfates, nitrates, ammonium, and magnesium.

X-Ray Fluorescence Spectroscopy

Handheld XRF’s are calibrated to analyze consumer goods for specific compounds related to RoHS requirements, but they are also a valuable non-destructive screening tool for various metals.

Fourier Transform Infrared Spectroscopy

The FTIR uses infrared radiation to scan samples. The infrared radiation is absorbed by the sample resulting in molecules in an excited state. The energy from the excited molecules is converted into vibrational energy, and molecules can now be identified. FTIR is a great tool to identify unknown materials, identify contamination, and decomposition. It is generally used for organic compounds for identification or to scan for contaminants and is useful as a screening tool.

High Performance Liquid Chromatography - UV/Vis, Fluorescence Detectors

HPLC is a quick and efficient analysis used to identify and quantify analytes in a sample. The HPLC separates analytes when the solvent (mobile phase) containing the sample is injected into the column (stationary phase). The column is packed with adsorbent material which separates the analytes as the sample makes its way through the column. Each analyte or compound has its own retention time which is the time it takes for a compound to travel through the column and reach the detector.

Retention time may vary due to conditions such as pressure or flow rate, solvent, temperature of column, and the type of column used in analysis. These conditions are important when using retention time to identify components within a sample. Once the components of the sample are separated and leave the column the compounds are detected.

The HPLC’s UV-Vis detector measures the absorption of a sample in the ultraviolent-visible spectrum at various wavelengths to identify analytes. Fluorescence detectors are more sensitive and selective, exciting a specific molecule. The emitted wavelength is a property characteristic of a specific compound.

Differential Scanning Calorimetry

DSC is used to compare the amount of heat required to increase the temperature of a sample to a reference. Melting points, glass transition, and melting point depression can be evaluated. Samples can be compared to each other and to standards for signs of altered or additional components or thermal properties.

Liquid Chromatography with Mass Spectrometry

The LC-MS/MS instrument is based on the HPLC. Liquid chromatography-mass spectrometry combines physical separation and mass analysis. The LC-MS separates compounds within a sample, and the mass spectrometer provides mass to charge ratio which is used to identify compounds. This technique is highly sensitive and is most useful for established methods especially to compare samples to each other and to standards.

UV/Vis Spectrometry:

UV/Vis uses visible light and ultraviolent to quantitatively measure a single analyte concentration in a sample. A beam of light of a specific wavelength passes through a cuvette that contains the sample solution, and the light is absorbed. The intensity of light is measured, and that intensity corresponds to the wavelength.

pH Measurements

pH Meters are used to measure acidity or alkalinity in solution. A pH sensitive electrode is used to measure the potential hydrogen ions. pH testing often complements other analytical techniques.

Microwave Digestion (Prep Technique)

Microwaves are used to digest heavy metals in samples using the combination of acid, high temperature, and high pressure. Once the metals are dissolved in the solution, the samples can be analyzed by ICP-OES.

Accelerated Solvent Extractor (Prep Technique)

The ASE speeds up the extraction of compounds from a complex matrix using high temperature and pressure.