Introduction
Mass spectrometry (MS) is a method used to analyse a sample and measure the mass-to-charge ratio thereof. It can be used to determine the mass of samples as well as the composition of the sample.
Liquid chromatography (LC) or more specifically known as high-performance liquid chromatography (HPLC) is a technique that makes use of chromatography to separate a mixture of complex compounds into its constituent molecules and can further be used to identify, quantify and purify these components.
The combination of MS and LC is a highly specialised analytical technique with high sensitivity and combines the separation capability of HPLC with the mass analysis of MS (COVEY, et. al., 1986). Liquid chromatography-mass spectrometry (LC-MS also known as HPLC-MS) can be used for the specific detection of a certain chemical substance in the presence of numerous other chemicals closely related to the required substance. Thus the identification of a certain substance in a complex mixture can be done (ARDREY, 2003).
Chromatography decreases analysis speed but offers two main benefits. Metabolites with identical masses, but different retention times, can be distinguished and the separation of metabolites from interfering substances allows for improved quantitative accuracy (LAST, et. al., 2007).
2. LC-MS
2.1 Principles of LC-MS and LC-MS/MS
The combination of the separation technique of LC allows pure compounds to enter the identification by mass spectrometry and therefore increases the chance of successful identification of an unknown substance. This is based on the principle that many compounds with identical retention characteristics have different mass spectra and in this way can be differentiated. The...
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...of sulfonamides. RSC publishing. 30:471-478
GATES, P. 2005. High performance liquid chromatography-mass spectrometry (HPLC/MS). Organic Chemistry Unit-Bristol Research Centre
LAST, R.L., JONES, A.D. & SHACHAR-HILL, Y. 2007. Towards the plant metabolome and beyond. Nature Reviews Molecular Cell Biology. 8:167-174
NANDAKUMAR, R., MADAYIPUTHIYA, N. & FOUAD, A.F. 2009. Proteomic analysis of endodontic infections by liquid chromatography-tandem mass spectrometry. Oral microbioligal immunology. 24:347-352
PRZYBOROWSKA, A. 2002. Introduction to Liquid Chromatography/ Mass Spectrometry and Liquid Chromatography/Mass Spectrometry/Mass Spectrometry (LC-MS/MS). King's College London, United Kingdom
ROSEN, J. & HELLENAS, K.E. 2008. Determination of the neurotoxin BMAA in cycad seed and cyanobacteria by LC-MS/MS. The Analyst. 133:1785-1789
The analysis is therefore one of the most effective methods of ensuring that each drug being prescribed to patients is safe. It also ensures that all drug components are understood in terms of their structure and chemical behavior. This understanding is very important in the manufacture of drugs and other pharmaceutical products.
Experiment 1: Find a connection between braces and canker sores by testing the microbiota using HOMIM.
Performing this experiment, we used the technique called Acid-Base extraction to isolate Eugenol, which is one of the main ingredients of clove oil. Acid-Base extraction is the most efficient method for isolating organic component; it is efficient because it purifies the acid and base mixture based on their chemical identities. We have seen throughout this experiment that acid and base play an important role, when it comes to solubility in water. Our basic knowledge of acid and base is acid is a proton donor and base is a proton acceptor. This ideology helps us to understand why organic compounds are not soluble in water. When compounds tend to be insoluble, we have to use acid and base reaction, to change its solubility. The changes that occurred
... of subjects with periodontitis: Candida albicans and Candida dubliniensis colonize the periodontal pockets". Med Mycol. 46 (8): 783–93. doi:10.1080/13693780802060899.PMID 18608938
...the mass spectrometer. This is called an electron impact source. Gases and volatile liquid samples are allowed to leak into the ion source from a reservoir. Non-volatile solids and liquids may be introduced directly. Cations formed by the electron bombardment (red dots) are pushed away by a charged repeller plate (anions are attracted to it), and accelerated toward other electrodes, having slits through which the ions pass as a beam. Some of these ions fragment into smaller cations and neutral fragments. A perpendicular magnetic field deflects the ion beam in an arc whose radius is inversely proportional to the mass of each ion. Lighter ions are deflected more than heavier ions. By varying the strength of the magnetic field, ions of different mass can be focused progressively on a detector fixed at the end of a curved tube. Because the mass of each individual ion
Separations are important techniques in chemistry that are used to separate various components of a mixture. They are carried out by mixing two immiscible liquids containing certain solutes together in a separatory funnel, allowing them to separate, then extracting the distinct layers that form. The ratio of the concentration of solute present in the upper layer to the concentration in the lower layer is called the partition coefficient. The efficiency of a separation is described by this partition coefficient. If the coefficients for the two layers are largely different, then the separation can be carried out in a single step. If they aren’t, a more complex process is necessary.1,2 Countercurrent chromatography is a technique used carry out separations in these kinds of cases. It uses a continuous liquid-liquid partitioning process to streamline the usual extraction procedure.
Chromatography has been developed over the past century and has an important contribution in many areas of modern science. However the main original work of M.S.Tswett was published in a book Chromatographic Adsorption Analysis.
Furthermore, an additional method to use other hydrochloric acids that have different concentration levels such as 1 M and 2.5 M ones, can improve the outcome of the results. This increases the variation of the independent variable, which accordingly increases the precision of results.
Saliva contains glucose; therefore, if you have uncontrolled diabetes, the amount of glucose present in your saliva is elevated. We naturally have somewhere between 200 to 300 bacterial species in our mouths: Some of these bacteria are good and some of them are bad. Streptococcus mutans is typically the bacterium responsible for causing tooth decay; whereas, periodontal disease is usually caused by a mixture of Porphyromonas gingivalis and Treponema denticola.
Ciguatoxin originates from dinoflagellate algae and most commonly from the coral reef species of algae called Gambierodiscus toxicus primarily in tropical and subtropical regions (Kipping, Eastcott, Sarangi, 2006). The algae are eaten by herbivorous fishes that absorb the toxin without any significant observable effect (Kipping, Eastcott, Sarangi, 2006). The toxins remain in all parts of the fish flesh but there are higher concentrations of toxin in the viscera, liver and gonads. Bioaccumulation occurs as ciguatoxin progresses up the food chain. The species of fish with the highest quantity of ciguatoxin are the larger predators, primarily sharks and barracouda (Dickey, Plakas, 2010). The process of digestion itself appears to potentiate the toxicity (Kipping, Eastcott, Sarangi, 2006). The toxin is odorless and tasteless. Contaminated fish have no distinct taste and are undetectable (Bavastrelli, Bertucci, Midulla, Giardini, & Sanguigni, n.d.). The ciguatera toxins are heat stable and thus are not destroyed by cooking, freezing or acid (Kipping, Eastcott, Sarangi, 2006). Pre-market testing for the presence of CTX is currently not possible due to a lack of existing rapid field testing methods (Report, 2013).
Other forms of finding a witch was by torture, were the accused would tortured by various devices for various amounts of time. Some of those devices include, the rack, thumbscrews, and the breast ripper. It is unknown what type of torture was used on Rebecca West. In the journal kept by Nehemiah Wallington, that torture was used to coerce a confession from her. It is not clear if Hopkins ordered her to be tortured or not. The witch-finder general, Hopkins, main method of extracting a confession from his victims was torture. In Wallington’s accounts he reported that the young Rebecca West, was tortured until she confessed to her accused crimes. Wallington states the following:
Infection control is a central concept to every practice of health care providers. Its main objective is to prevent the transmission of infectious diseases from both patients and health personnel (Martin et al., 2010). In dental clinic, infection control is a continuous concern for its professionals. They have to contact patients routinely and be exposed to their blood, saliva, dental plaque and pus that may contain infectious pathogens. It is important for the dental professionals to treat these fluids as if they are infectious and special precautions must be taken to handle them. In this essay, I will highlight the scope of infection control practices in dental clinics and the ways through which infectious microorganisms are transmitted in the dental clinic. Also, I will talk about some infection control guidelines implemented in dental clinics and how they meet the needs of the patients. Finally, from a personal perspective, I will mention some factors that affect the implantation of infection control guidelines and procedures.
The choice of mobile phase depends on the chemical nature of the compound of interest and could be purely organic, inorganic or a mixture of both in gradient. Most commonly used mobile phases are organic solvents like acetonitrile or methanol. Some HPLC analysis require the use of water free solvents as mobile phase and in such cases acids like formic acid, phosphoric acid, trifluoroacetic or salts which will assist in separation of components in the sample are used.
Mass spectroscopy originated in 1919 by a British scientist named Francis Aston when a machine was created for the purpose for measuring the proportions and masses of the atomic species in part of a sample. A mass spectrometer is an instrument that measures the masses of individual molecules that have been converted into ions e.g molecules that have been electrically charged. A Mass Spectrum is a plot of ion intensity as a function of the ion's mass-to-charge ratios. Spectroscopy is a diverse and complex branch of science. It has many uses and is widely acknowledged as an essential part of development in the world of science.
Office of Pharmaceutical Science (2005). Process Analytical Technology (PAT) Initiative. Retrieved on October 08, 2005 from http://www.fda.gov/cder/OPS/PAT.htm