Laboratories in CLU
- Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM/EDX) Spectroscopy
Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX) is the best-known and most widely-used of surface analytical techniques.
High-resolution images of surface topography, with excellent depth of field, are produced using a highly-focused, scanning (primary) electron beam. The primary electrons enter a surface with an energy of 0.5 – 30 kV and generate many low energy secondary electrons. The intensity of these secondary electrons is largely governed by the surface topography of the sample. An image of the sample surface can thus be constructed by measuring secondary electron intensity as a function of the position of the scanning primary electron beam. High spatial resolution is possible because the primary electron beam can be focused on a very small spot (<10 nm). High sensitivity to topographic features on the outermost surface (< 5 nm) is achieved when using a primary electron beam with an energy of <1 kV.
- Transmission electron microscopy (TEM),
transmission electron microscopy is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie the wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method in the physical, chemical, and biological sciences.
- Inductively Coupled Plasma/ Mass Spectrometer (ICP/MS)
ICP-MS is a powerful Analytical technique, which is capable of
detecting the concentration of metals and non-metals with their
isotopes at concentrations level as low as parts per billion ppb and parts
per Trillion ppt.ICP-MS has found wide application to the analysis of a variety of
samples, including water, food, geochemical, environmental,
biological samples, Clinical, Chemical/Petrochemical, Pharmaceutical,
Forensic, Geological, and Archaeological - Inductively Coupled Plasma - Optical Emission (ICP- OES)
Inductively coupled plasma - optical emission spectrometry, is a
the technique in which the composition of elements in samples can be
determined using plasma and a spectrometer.
- Ultraviolet and Visible Spectrometer (Lambda, Perkin Elmer). Equipped with a double-beam heated flow cell, which allows kinetic study and accurate quantification of UV-absorbing organic and inorganic compounds. UV-Visible Spectrometer is used for the determination of ammonia, nitrate, nitrite, sulfate, silicate, cyanide in water and food. Also, it is used for the determination of plant pigments (chlorophylls and carotenes) and biological compounds (sugar and proteins) and aromatics and Metallo-organics.
- FTIR Spectrophotometer 760 Nicolet and 670 Thermo Nicolet: determine compounds based on the absorbance in the Mid-IR (4000-400 cm-1) and Far-IR 600-5 cm-1. FTIR spectrophotometer can identify the functional groups (alcohol, carbonyl, carboxyl, ester, ether, cyanide...etc). This instrument can analyze samples as solid, liquid or gaseous. Thus, this instrument is useful for the analysis of petroleum products, drugs, paints, detergents, oils, fibers, and polymers. Electronic libraries equipped with the Nicolet instruments allow fast identification via matching the obtained result with the one available in the library.
- Gas Chromatography (GC) Instruments: samples injected must be gaseous or volatile liquid such as petroleum and natural gas, pesticide, volatile organic pollutants, alcohols, and explosive residues that are converted into gaseous such as nitrobenzene and TNT. The GC instruments are equipped with four types of detectors:
- Flame Ionization Detector detects all hydrocarbons except those containing carbonyl and carboxyl
- Electron Capture Detector is sensitive to halogen-containing molecules, conjugated carbonyl, nitriles, nitro compounds, organometallic compounds, but relatively insensitive to hydrocarbons, alcohols, and ketones;
- Thermal Conductivity Detector can respond to all analytes that are separated in the gas phase, but it is less sensitive compared with other detectors;
- Nitrogen-phosphorous Detector (NPD) is sensitive to compounds containing N and P and is particularly important to drug, pesticide and herbicide analysis.
- Liquid Chromatography (LC) Instruments: samples injected are liquids and the lab contains: 1- HPLC that separate based on the polarity of solutes and it can be applied to separate drugs, plant pigments (chlorophylls and carotenes); 2- gel permeation chromatography separate polymers, sugars and proteins and other biological compounds based on molecular size; 3- Ionic Chromatography, Model DZ-600 which is used to separate anions(F-,Cl-, NO2-, NO3-, and SO42-) and cations (Li+, Na+, NH4+, and K+, Ca2+) in aqueous solutions
- Organic Elemental (CHNS/O) Analyzer from Perkin Elmer Model II series 2400 identifies organic compounds through the determination of their elemental ratio (C, H, N, S, and O) that are converted into gas molecules after they are burned. The solid sample that can be burned and analyzed are between 2-5 mg. Relative amounts of carbon, hydrogen, nitrogen, sulfur, and oxygen can be determined. Therefore, this instrument is useful for the analysis of organic synthesized molecules and food and nutrition studies.
- Pyris 6 Thermo Gravimetric Analyzer (TGA) measures weight changes of the sample (1-5 mg) as a result of temperature change or as a result of time at a constant temperature. The temperature of TGA can reach 900°C. TGA measurement can be used to identify the structure for many organic and inorganic compounds. Other study areas which can be conducted by TGA are:
- Identification of filler and content of material by weight%.
- Quantify the material’s loss of water, solvent, or plasticizer within a certain temperature range.
- Examine flame retardant and combustion properties of materials.
- Fingerprinting
- Perkin Elmer DSC 7 Differential Scanning Calorimeter (DSC)measures the thermal response of an unknown specimen as compared with a standard when the two are heated uniformly at a constant rate. Any difference in temperature of the two specimens is caused by differences in mass, specific heat, heats of reaction, or phase transitions.DSC is used to measure specific heat capacity (100 to 1200oC)and heats of transition as well as to detect the temperature of phase changes and melting points in the range of 20 to 1500oC. Specific heat capacity can be used in conjunction with thermal diffusivity to obtain thermal conductivity.
The NMR spectroscopy has become one of the essential and the most powerful analytical technologies in chemistry, especially in organic chemistry and organometallics, majorly for the chemical structure identifications. NMR measurements have also been widely used in many related fields, including but not limited to materials science, pharmaceutical developments, food, and biomedical applications, petroleum industry, agriculture, forensic science, etc.
