Use of Liquid Chromatography-Tandem Mass Spectrometry - Coursework Example

Simultaneous Determination of Eight Illegal Dyes in Chili Products by Liquid Chromatography-tandem Mass Spectrometry Institutions name Class Date 1. Produce a 500 word review of the paper. This was a sensitive paper that employed an accurate method, which was based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) use. The method was used to simultaneously determine the eight illegal synthetic dyes used in the experiment as solvents (Juan Lia et al. 2013). One of the dyes that were being sought for in the experiment was Sudan dyes. These are synthetic azo dyes commonly in industries despite the fact that they have been found to be contaminating foodstuffs (Juan Lia et al. 2013). This paper could have informed its readers more about the negative effects of Sudan (I–IV) use so that those who intend to perform the experiment at home can be informed about its harmful effects. Cross- contamination or adulteration is one of the main foods contaminating process in the due use of Sudan dyes (Juan Lia et al. 2013). This experiment ought to have taken pre-cautions to inform its readers on the harmful effects of these eight illegal dyes in chili products. Spectrophotometric method could have been discussed somewhere in this paper as a way that can be used to detect the presence of Sudan dyes and other illegal dyes in chili powders or any other food stuff in ppm levels (Juan Lia et al. 2013). This method has been found reliable in identifying and estimating the level of sudan I-IV in Chili samples. Ethyl acetate is yet another useful solvent used to extract dyes from chili samples as well as the preparation of samples. The eight illegal dyes discussed in this paper cause carcinogenicity which is a high producing capacity among many other ailments. Otherwise, the paper developed the HPLC-MS/MS chronologically from the first to the last step demonstrating the extraction procedure used to determine eight illegal synthetic dyes in chili products simultaneously. The selection of MS/MS technique combined with chromatographic separation was an accurate method of determining compounds in complex matrices with less ambiguity (Juan Lia et al. 2013). The method was effective that it did not require the laborious clean up procedures. The method was highly accurate with a good repeatability. The detection of any limits like quantification limits was minimal (Juan Lia et al. 2013). The HPLC-MS/MS process employed in the paper proved to be effective for fraud detections in both exported and imported chili products. The analysis of data was done effectively through the use of graphs and tables to illustrate the results. The chemical structures of the eight illegal dyes analysed were also illustrated in both structures and writing for easier understanding of the readers. This paper is a discussion Simultaneous Determination of Eight Illegal Dyes in Chili Products by Liquid Chromatography-tandem Mass Spectrometry by Juan Lia, B. Xiao-Ming Dinga, B. Dan-Dan Liua, B. Fei Guoa, B. Yu Chena, B. Yan-Bing Zhanga, B. Hong-Min and Liua, B, (2013). The specific area of consideration will be to comment on polarity of aceto nitrile; water solvent used to extract the colors and why the solvent mixture was considered in the six solvents investigated. Second, a comment will be given on why some recoveries exceed 100% in figure 2; showing recovery of food colors with different solvents. Third, the student will comment on why stmmetrical peak shapes was preferred in section 3.2. Fourth, the chromatograms used in figure 4 will be analysed to identify why they have multiple peaks. Fifth, the differences between LC-MS/MS and LC-MS will be given and finally the concept ‘tandem technique’ will be discussed in details. 2. Comment on the polarity of the aceto nitrile/water solvent used to extract the colors. Why do you think this solvent mixture was considered in the group of six solvents investigated? Acetonitrile exhibits the lowest absorbance for shorter wavelengths (Fonovich 2013). The organic solvent with the lowest absorbance is the best to use for mobile phases like chromatography because they produce the lowest noise while detecting the UV light (Fonovich 2013). Acetonitrile is meant to be used for analysing short UV wavelengths with high sensitivity. The solvent mixture was also considered in the group of six solvents investigated because it is effective in less ghost speaking for gradient baselines (Fonovich 2013). Hence, Acetonitrile has a lower absorption rate as compared to other organic solvents, which have high compatibility with water. 3. Figure 2 show recovery of food colors with different solvents. Comment on why some recoveries exceed 100%. The reason why some recoveries exceed 100% in figure 2, which shows recovery of food colors with different solvents is that different dyes and solutes travel best along the chilli products with some solvents and worst with others (Christie 2001). Every solute has a specific RF value for the specific solvent involved. In addition, the concentration of the solvent is important in determining the recovery of the food color (Christie 2001). Pigments with a better RF value tend to go far from the application point just like those that exceeded the 100%. 4. Section 3.2 talks about “symmetrical peak shapes” – why is this desirable? The symmetrical peak shape is desirable because it will assist in the achievement of the accurate quantification target of trace components in the experiment (Pardo & Pastor 2009). These components are usually 0.1% or less in the whole mixture. 5. Some chromatograms in figure 4 have multiple peaks. Why might this be? Some chromatograms in figure 4 have multiple peaks to show the various concentration rates of the compounds use in the experiment. The small peaks indicate low percentage and broad height-ed peaks indicate high percentages of the compounds (Pardo & Pastor 2009). The multiple peaks give one a rough idea of the compounds in the Chili Products.  6. What is LC-MS/MS and how does it differ from LC-MS? Liquid Chromatography-mass spectrometry (LC-MC) is a technique used in chemistry to analyse liquid chromatography through the combination of physical separation capabilities (Mustafa et al. 2013). The technique has a powerful technique that is highly sensitive and selective making it useful in various applications. The techniques separate, detects and identifies particular chemicals present in other chemicals. Prepared LC-MS systems are useful to purify specific substances from important basic research foods, pharmaceutical and agrochemicals amongst other research basics (Mustafa et al. 2013). Liquid chromatography-tandem mass spectrometry (LC MS/MS) is used to analyse specific superior immunoassays. The technique is very useful in clinical laboratories. LC is used to assess all masses coming from an LC trace’s peak (Mustafa et al. 2013). LC-MS/MS on the other hand is used to select a single mass from one’s results of LC-MS. The result is often the highest. The spectrometer is used to separate the parent, fragment it and illustrate the mass’s daughter ions (Mustafa et al. 2013). With two different compounds with different masses coeluting, LC, LC-MS/MS is he best technique to find out the mass spectra data of every compound. 7. This paper describes a “tandem” technique. Explain the concept of tandem techniques and provide several examples of their use in analytical chemistry. Tandem techniques engage a number of steps of selecting mass spectrometry (Wang et al. 2013). During the selection process, some form of fragmentation occurs in between the stages. There are several examples of tandem instruments used in analytical chemistry as illustrated below (Wang et al. 2013). Tandem MS instruments involve multiple stages of separating mass analysis. This is usually accomplished with one mass spectrometer elements, which are separated by a mass spectrometer. The process involves separating the MS steps in time (Wang et al. 2013). Tandem in space: the separation elements are distinctively and physically separated. During the process, there is usually maintenance of high vacuum through a physical connection between the elements (Wang et al. 2013). Time of flight, sectors and transmission quadrupole are just a few examples of elements involved in the process. Incase multiquadrupoles are used; they can play the roles of collision chambers and mass analysers (Wang et al. 2013). Tandem in time involves accomplishing the separation through trapping ions in the same place and with several separation steps taking place one after the other. The FTMS instrument or a quadrupole ion trap is used to analyse this process (Wang et al. 2013). Multiple steps of analysis are performed with the trapping instruments. Sometimes the number of steps is not specified, but in such case the value has to be specified. For example, MS3 illustrates three stages of separation (Wang et al. 2013). There are various tandem experiments as illustrated below; Tandem MS modes, this experiment involves product ion scan, precursor ion scan, neutral loss scan and selected neutral selection (Wang et al. 2013). In product ion scan, the selection of the product takes place at the second mass analyser while scanning of the precursor masses happens at the first mass analyser. Parent ion and precursor ion are synonymous while daughter ion and product ion are synonymous (Wang et al. 2013). In precursor ion scan, the selection of the first ion takes place at the first stage. The ion is fragmented before the scanning of all masses in the second mass analyser which are detected afterwards in the detector situated closer to the second mass analyser (Wang et al. 2013). The technique is useful in identifying quantification transitions. The neutral loss scan scans all masses in the first mass analyser. The scanning of the second mass analyser takes place at a set offset from the former (Wang et al. 2013). The second scanning corresponds to neutral losses, which are common in class compounds. There is also monitoring of every precursor undergoing the loss of a specific common neutral. This technique is useful in selecting identities, which are closely related to a mixture containing a class of compounds (Wang et al. 2013). Selected reaction monitoring involves setting mass analysers to a selected mass. This technique is similar to some specific MS experiments for ion monitoring (Wang et al. 2013). This analysis mode is very selective due to its high sensitivity. References Christie, RM, 2001, Colour chemistry. Publisher, Royal Society of Chemistry, London. Fonovich, M, 2013, “Sudan Dyes: Are They Dangerous for Human Health?” Drug and Chemical Toxicology, vol. 36, no. 3, pp. 343-352. Juan Lia,B Xiao-Ming Dinga, B Dan-Dan Liua, B Fei Guoa, B Yu Chena, B Yan-Bing Zhanga, B Hong-Min Liua, B, 2013, “Simultaneous Determination of Eight Illegal Dyes in Chili Products by Liquid Chromatography-tandem Mass Spectrometry,” Journal of Chromatography B, vol. 1 , no. 1, pp. 46-52. Mustafa, S Khan, RA Sultana, I Nasir, N & Tariq, M 2013, “Estimation of para red dye in chilli powder and tomato sauces by a simple spectrophotometric method followed by thin layer chromatography.” JASEM vol. 17, no.2, pp. 177-184. Pardo, O & Pastor, A, 2009, “Development of a Method for the Analysis of Seven Banned Azo-Dyes in Chili and Hot Chili Food Samples by Pressurised Liquid Extraction and Liquid Chromatography with Electrospray Ionization-Tandem Mass Spectrumetry,” Talanta, vol. 78, pp. 178-186.  Wang, J Zheng, Z Zhang, T Wang & Che, B, 2013, "Determination of Eight Sudan Dyes in Chili Powder by UPLC-MS/MS," Engineering, vol. 5, no. 10B, pp. 154-157. Read More