Laboratories in CLU
It contains a Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). The ultra-high magnifications of TEM have made it a valuable tool in medical, biological and materials research. It is now possible to see internal structures of objects as small as a few angstrom units (10-10 m). Detailed studies of cells or different materials can be done in near nanometer levels.Scanning Electron Microscope (SEM) is relatively new, funded by Qtel in 2006. It is used to study the surface microstructure of biological and materials specimens. SEM creates images by focusing a high energy electron beam onto the surface of samples and produce high-resolution images, which help in understanding the surface morphology. In conjunction with an X-ray Energy Dispersive Spectroscopy device (EDAX-EDS), qualitative and semi-quantitative elemental analysis can be done on the sample under investigation. SEM is used for the surface morphology study of a wide range of specimens, with use in biological, biomedical and material sciences. It has the ability to magnify typically to 200,000 times.
- Inductively Coupled Plasma/ Mass Spectrometer (ICP/MS) is Agilent 7500-CE equipped with a collision cell, which works on eliminating interference and optimizing signals. This instrument can analyze metallic elements in the aqueous samples. Most heavy metals in the periodic table (Pb, Ni, Cu, Mg, Mn, Cd, Co, Sn, Sr,…etc) can simultaneously be measured. The detection limit can reach part per trillium. Non-aqueous samples can be digested and dissolved in the lab prior to the analysis by ICP/MS. Isotope ratio can also be determined by ICP/MS. Therefore, the instrument has a wide range of applications related to environmental study, madison, quality control, and safety monitoring, as well as toxicity in drinking, ground and seawater and beverages. The age of rocks may be determined by measuring the ratio of87Sr/86Sr. Pollution with radioactive uranium can be monitored by measuring the ratio of 235U/238U.
In addition, ICP/MS is a very useful tool to determine metal residue in the human body resulting from eating habits and environmental exposure. In order to optimize the performance of the ICP/MS in the CLU, high-grade gases (grade 5) are used and super pure nitric acid is used for the introduction of the sample. Also, highly pure deionized water (resistance = 18.2 MW) is prepared using the Millipore water preparation system. - Atomic Absorption Spectrometer (AAS) from Perkin Elmer 700equipped with two types of atomization devices (Flame and Graphite Furnace). AAS detects elements based on the light absorbed and has similar applications to that for ICP/MS. However, unlike ICP/MS, AAS cannot be used to measure the isotope ratio. It is used for the analysis of elements in aqueous solutions. Graphite furnace can be used for the analysis of organic samples directly and often without the need for digestion. The detectable concentration is higher for AAS when compared with that for ICP/MS. The lowest concentration that can be detected by Falme-AAS is ppm, whereas ppb can be detected by Graphite Furnace -AAS. AAS is more tolerant of a high-concentration sample and is less susceptible to damage caused by suspended particles when compared with ICP/MS. Therefore, sample preparation is less tedious when using Falme-AASand organic samples can be introduced directly (no digestion step) when graphite Furnace –AAS is used. AAS can, therefore, be used for the analysis of heavy metals in blood, milk, beverages, groundwater and treated sewage water. In addition, AAS is used for the analysis of heavy metal in soil, rocks and construction materials which require digestion prior to analysis.
Molecules are determined qualitatively and quantitatively as a result of light absorption. The instruments available are:
- 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.
It contains types of equipment that separate and determine analytes in gas and liquid phase qualitatively and quantitatively.
- 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.
It contains a JEOL JNM-ECZR series 600 MHz FT NMR spectrometer equipped with a broadband liquid probe, solid probe, and variable temperature (VT) unit.
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.
