a)You work for an environmental laboratory conducting screening of wastewater for potential contaminants. The laboratory currently possesses a reverse-phase liquid chromatograph but is considering purchase of an ion chromatograph. Provide an argument for the laboratory’s procurement officer that purchasing an ion chromatograph would extend the laboratory’s analytical capabilities. Your answer should make use of appropriate annotated diagrams. Analysis of wastewater is a crucial component of analytical and environmental chemistry. Both the traditional wet procedures and instrumental approaches can be used to execute it. A significant responsibility for researchers is the creation of new methodologies and the modification of those already in use. The instrumental methods for determining ions mostly use ion chromatography. It has a number of benefits over traditional wet method approaches, including: quick analysis times (between 10 and 15 minutes); high sensitivity and selectivity in samples with complex matrices (for example, if the ratio of Na+:NH4+ or Cl:NO2 is 10,000:1); ease of sample pre-treatment (typically filtration with a 0.45-µm pore size is sufficient); and potential for simultaneous separation and determination Moreover, alkali and alkaline earth cations as well as ammonia may be determined simultaneously using ion chromatography. Spectroscopic techniques cannot be used to identify ammonium ions. Inorganic anions and cations are often determined using ion chromatography in wastewater analysis Due to its ability to replace several separate wet chemistry procedures for common ions with a single experimental approach, ion chromatography has gained acceptance around the world as a reference method for assessing anions and cations in water and wastewater. For determining inorganic and organic ions in wastewater, ion chromatography offers a number of advantages over traditional wet methods[9]. DISADVANTAGES OF RPLC • High relative investment and Materials cost is high • Non-destructive methods non-selective techniques • Performance depends on the type of material • numerous different types of adsorbents are necessary. • Chemical derivatization to increase their ability for adsorption • Rapid reactor saturation and blockage (regeneration costly) • Ineffective with certain metals and some kinds of dyestuffs • Adsorbent removal (needs material replacement, regeneration, or cremation) • Regeneration is costly and resulting in material loss • economically unviable for some industries (textile, pulp & paper, etc.)[10]   b)You are an analytical chemist in a forensic laboratory. You have been tasked with analysing fire debris for volatile hydrocarbons that might be indicative of a chemical accelerant. a)Which mode of chromatography would you recommend for this purpose, and why? Justify your answer. The process of analysing accelerants in fire debris entails separating the remaining volatiles from the matrix and analysing them, often using gas chromatography (GC). A library of accelerant chromatograms produced under comparable circumstances is compared to the resultant chromatograms to interpret them. The most recognised chromatograms are those that have distinct n-alkane homolog patterns. Chromatograms with too much interference can be improved by physically removing or reducing the interfering substances or by selective detection, whereas those with insufficient resolution can be enhanced by columns with better efficiency or selectivity[11]. The presentation of common ions shared by compounds with similar structural properties is made possible by using a mass spectrometer (MS) as the detector in GC-MS applications. This substantially facilitates the practise of pattern recognition. For the automatic identification of patterns shown by different kinds of accelerants, computer methods are currently available[12]. b)The evidence submitted is a swatch of carpet in a sealed container. How would you sample potential volatile hydrocarbons from this material? Justify your approach. The sample analysis and data interpretation is the most challenging step of fire debris analysis, due to the presence of combustion and pyrolysis products in the substrate material here swatch of carpet. That is why, the extraction of combustion and pyrolysis products from carpet substrate materials—typically consisting of nylon 6,6 and polyesters—was done using a headspace solid phase microextraction (HS-SPME) approach. Prepare a sample A diluted stock solution of ILs was initially made in order to prepare the samples. The Ignitable Liquid (IL), either gasoline or kerosene, was added to a 1.00 mL quantity of a 9:1 combination of methanol and ethyl acetate, vortexed for one minute, and then chilled. 10 µL of the diluted IL(ignition liquid) stock solution and 2 mL of deionized (DI) water were added to a 10 mL septum screw cap vial to create the IL sample for SPME extraction. For the head-space analysis of all samples, the HS-SPME approach was examined by . Before the preconditioned DVB/CAR/PDMS fibre was put into the cap septum and exposed to the head-space of the sample separations for 30 minutes, each sample was first incubated at 30 °C for five minutes. The fibre was then taken out and placed into the gas chromatogram injector at a temperature of 250 °C for two minutes of desorption. Using the XCalibur software, the extracted ion profiles and total ion chromatograms were acquired for each sample. By comparing the fragmentation pattern of the unknown mass spectrum with the reference mass spectra in the NIST collection, the target chemicals and pyrolysis products were found. Reverse Match Factor is presented as the mass spectrum matching score (RSI)[[13]. C) Using media or internet sources, identify and describe a “real-world” problem in which gas chromatography, liquid chromatography, or ion chromatography was used to achieve separation of analytes in a mixture. STUDY -On-line dialysis-double suppression ion chromatography has created a quick, exact, and accurate technology that can concurrently identify seven anions in whole blood. The selection of protein precipitant in samples, the amount of filtrate discarded, the choice of eluent flow rate, the influence of the Ag-Na column on experimental results, the influence of ethylenediamines on ClO2, and the investigation of nitrogen drying are performance parameters that could affect the determination of anions. Finally, sodium carbonate with a concentration of 3.6 mmol/L and a flow rate of 0.8 mL/min was chosen as the eluent to separate the 7 anions. The proteins in blood were precipitated using blood and alcohol (v/v, 1:4). The first 2 mL of the C18 column's filtrate were discarded after the 7 anions' recovery rate had reached a sufficient level. At LLOQ, low, medium, and high concentrations, the recovery rate ranged from 80 to 120%[14]. ANALYTES – fluoride, chlorite, chlorate, nitrite, nitrate, bromide and sulfate anions Sample matrix contains Dextran, polystyrene, Cellulose with functional group (Trimethyiaminomethyl, Triethylaminoethyl )[15] CHOICE OF METHOD – beacauseThis method has simple pretreatment, high accuracy, and good reproducibility and selectivity, and is suitable for the separation and determination of anions in blood. Choice of detector- Conductivity detectors The primary detection method used in ion exchange chromatography is conductivity detection. For charged species present in the mobile phase, it enables an all-encompassing detection method.The mobile phase's conductivity is influenced by the medium's temperature, ionic strength, and the types of ions that are present. The disparity between the conductivities of the ionised species present and the mobile phase's composition will have a significant impact on the sensitivity of detection.