Analytical Chemistry

Clark specializes in routine analysis and comprehensive investigative chemical testing for the steel and related industries. The Analytical Chemistry Lab ensures high quality performance through analytical expertise, documented test procedures, and stringent quality assurance standards.



Clark is currently accredited under ISO/IEC Guide 17025 standards. All testing is performed in accordance with ASTM, API or other approved applicable methods. Additionally, we have experience utilizing chemical techniques to develop new methods.

Clark routinely analyzes ferrous and nonferrous metals, metallic and organic coatings, process solutions, petroleum products, and surface cleanliness of steel. Other capabilities include analysis of raw materials and by-products such as steel additives, fluxes, ceramics, refractory, slag, lime, pellets, scrap, bag house dust, coal and coke, as well as other industrial materials for composition and/or contamination.

Testing Services Available
Inorganic Testing Services Alloy Analysis, OE/ICP Coal Ash, XRF Coating Composition, ICP Metal Fines on Sheet, ICP Metal Oxides, XRF/ICP Metallic Soaps on Sheet, ICP Metals, OE/ICP/AA Slag/Refractory/Ore/,XRF Surface Cleanliness Ion Chromatography C, S, O, N by Combustion Forms of Carbon, LECO Phase Identification, XRD Macro Etch Sulfur Print Silicon Carbide	Organic Testing Services BETX HPLC Oil Film Weight Total PCBs	Wet Chemistry Acidity Alkalinity Ammonia Forms of Sulfur Forms of Iron Loss on Ignition Moisture Determination Oil Film Weight, Iron Fines & Soaps Total Suspended Solids PCA Determination Percent Solids pH Reactivity Steel Coating Analysis Total Dissolved Solids Trace Chlorine	Specialty Testing NACE Tensile

Density
The Micromeritics AccuPyc 1330 helium pycnometer determines powder and solid densities. After properly preparing the sample with heat and/or vacuum, helium gas fills the sample chamber and pressure is measured. The helium then enters another empty chamber and the pressure in both chambers is measured. The sample volume is calculated based on these pressures and then with the known weight of the sample, the density is then calculated. The helium is able to fill all spaces and all but the smallest micropores open to the atmosphere.

Importance:
Changes in vendor materials or in processing could affect the density of the product. The helium pycnometer rapidly determines the apparent density of raw materials or finished product and when compared to a known standard, will indicate changes in the product.

Results:
A detailed report illustrates the volume and density of the analyzed sample.


Moisture Analysis
Moisture content of a sample is determined by heating a sample to dryness and then calculating the moisture loss. The calculations used to arrive at a result are based on weights taken before and after drying the sample. Moisture analyses are performed on the Mettler LJ16 moisture analyzer. The format of the results are reported as percent (%) moisture.

The need for moisture analysis spans the range of industries, such as the pharmaceutical industry, that uses powders to formulate a product. Flow characteristics of a powder are affected by moisture gain/loss and can result in many hours of lost production time. Moisture analysis is one of the most cost effective methods used to track powder characteristics.


Particle Size Analysis
Instrumentation:
The HORIBA® LA-920 Particle Size Analyzer is a laser light scattering instrument that combines a He-Ne laser with a Tungsten lamp to determine particle size in the range of .02 um to 2000 um using Mie Theory. Analyses can be performed wet or dry.

The HORIBA® LB-550 is a dynamic light scattering analyzer that has a range of 0.001 um to 6 um and uses the Fourier-Transform/Iterative Deconvolution technique for data reporting. Sample concentrations from ppm to 40% solids can be analyzed easily.

The Shimadzu SA-CP3 particle size analyzer analyzes samples in the 0.02 um to 500 um range by centrifugal photo-sedimentation using Stokes Law. Sample and dispersant density as well as dispersant viscosity must be known for this type of analysis.

Computer controlled scanning electron microscopy (CCSEM ) is performed by first mounting the sample on a filter and then scanning the sample with an electron beam and detecting particles based on the intensity of backscattered signals. Particle size data obtained during the scanning is grouped by the computer into size classes and number and mass distribution tables are generated.

Sieving analyses can also be performed using a Tyler sieve shaker.

Importance:
Particle size analysis is an important tool in determining the reactivity, flow characteristics, fusing qualities, shrinkage of ceramics, and many other formulation characteristics in just about every industry. Particle size analysis plays an important role in our lives. Please feel free to e-mail us with questions regarding particle size analysis.

Results:
Tabular data, a cumulative graph, and an incremental graph make up the sample report. Also included is a method report detailing the conditions of analysis.


Porosimetry
Nitrogen Porosimetry:
Instrumentation:
Micromeritics ASAP 2000, ASAP 2010, and ASAP 2400 analyzers determine pore information by condensing nitrogen in the pores of a material and then calculating the pore volumes from the quantities of gas required to fill the pores. Analyses are usually performed in conjunction with surface area analysis. For porosimetry analyses, the instrument doesn't stop with the first adsorbed layer of gas that is needed for surface area determination. Instead, the instrument continues to fill the sample with gas until bulk condensation begins.

Results:
A typical report consists of an adsorb/desorb isotherm, tabular data, and graphs illustrating pore values.

Mercury Porosimetry:
Instrumentation:
The Micromeritics Autopore IV 9500 measures pore diameters in the 0.003 um - 360 um range. This method of structure analysis is faster than nitrogen porosimetry. Since this analysis requires pressures of a maximum of 60,000 psia and uses mercury, not all materials can be analyzed by this method. With mercury porosimetry, pore information is obtained by forcing liquid mercury into pores by increasing the external pressure. As the pressure is incrementally increased, the amount of mercury required to fill the pores is recorded. This information, as well as information concerning the contact angle, is used to calculate the pore structures.

Results:
Pore area and pore volume graphs, as well as, bulk density, skeletal density, and porosity values are all reported.


Surface Area Analysis
Instrumentation:
Micromeritics ASAP 2000, ASAP 2010, and ASAP 2400 analyzers perform surface area measurements by the static volumetric method. When analyzing samples on these instruments, the samples are first out-gassed using heat and/or vacuum. Typically, nitrogen is the analysis gas for the surface area measurements; however, krypton is available for very low surface areas.

Micromeritics FlowSorb II 2300 performs single point surface area measurements by the flowing gas method producing quick and accurate results.

Micromeritics TriStar 3000 gas adsorption analyzer provides surface area measurements in a fast and efficient manner using a three sample station set up.

Importance:
The surface area of materials is important to the formulator of compounds ranging from aluminas to pharmaceuticals to catalytic supports and ceramics. For example, the dissolution time of drugs may be determined by surface area.

Results:
Reports vary from approximately 5 pages for a 5 point surface area (B.E.T or LANGMUIR) to one page for a single point surface area report.