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Ion exchange Chromatography as QC ^0 QA in diary Industry.pdf

  1. Ion Exchange Chromatography as QC, QA & QA in Food Industry Hajira Mahmood
  2. Introduction ▪ Important analytical technique for the separation and determination of ionic compounds ▪ robust and time-saving technique for multicomponent analysis in foods and beverages ▪ superior to single component analytical techniques and less complex than hyphenated techniques, but highly specific, precise, robust, and easy to use. ▪ capable of separating similar types of molecules that are difficult to separate otherwise ▪ very high resolution ▪ deal for the separation of charged biomolecules, including proteins, polypeptides, nucleic acids etc. enhanced productivity, reduced costs, and achieve accurate, reliable, and robust results.
  3. Conventional analytical procedures GC-MS Ion exchan ge RP chromato graphy Mass spectro metry Liquid chromato graphy Liquid chromat ography Paper Chromat ography Ultra HPLC- MS Eliminates carbohydrate Lithium buffer system Post-column system Minimal time for sample preparation New off-line sample preparation method Available Solution
  4. Principle of ion exchange chromatography ✓ Separates ions & polar molecules based on their affinity to the ion exchanger ✓ The charge carried by the target molecule facilitates the process of separation •Anion exchanger — 0.5–1.5 pH units greater than the isoelectric point, pI of the protein of interest •Cation exchanger — 0.5–1.5 pH units less than the pI of the protein of interest
  5. Glass, stainless steel, titanium, iner t plastic or high- quality polymer. protective layer, extends the life of the column reduces the background conductivity estimate the analyte peaks pre-programmed computing integrator Sample injection to deliver and maintain a constant flow Instrumentation
  6. Applications in Food Industry ✓Most active and creative fields in food and fermentation industry ✓play a pivotal role in the development of the food industry ✓ In juice, dairy, brewing & starch industry used to remove the heavy metal ions & nitrate ions, for deacidification, decolorization, demineralization & for the purification of food products.
  7. Phosphorus critical dietary mineral, involved as phosphate in bone, tooth, nucleic acids or phospholipids mainly supplied through consumption of dairy products. The objective of the study is to assay phosphorous in different dairy products i.e milk, aqueous phase of acidified milk & 3 types of cheese including one processed cheese containing poly phosphate salt. To mineralize the samples so that all phosphate is converted to orthophosphate which react with ammonium molybdate to finally yield molybdenum blue. Values are then compared with International Organization for Standardization (ISO) method Qc, QA & QA
  8. Experimental Conditions • IonPac AS11 hydroxide selective anion-exchange column, • AG11 guard column • ASRS 300 suppressor that helps increase sensitivity through trapping contaminating ions from the mobile phase • sample load: 25 µL injection volume • Temperature: 30°C • Flow-rate of the mobile phase: 1 mL/min. • Calibration curve • mineralized KH2PO4 solutions of phosphorous~450 mg/L of KH2PO4 • correlation coefficient R2 of the calibration curve was 99.7% • standard deviation was <0.02mg/kg
  9. Sample collection, Preparation, Processing In IEC only small amount of the samples (about 2mg/kg of phosphate) are required Chemical required only HCl & NaOH for the preparation of the sample Parameters Skim milk Ultra Acidified Milk Cheese Dry matter determination 5 g 10g 2 g Ashes measurement 5 g 10 g 2 g Total phosphate 5 g 10 g 2 g
  10. Sample Processing . (Csapo et al., 2008)
  11. Results & Discussion ▪ skim milk values were in the range of those reported for milk ▪ Compared to skim milk, the AMU had a lower dry matter of 54.6 g/kg, contained 6.4 g/kg of ashes and virtually no proteins. ▪ Contents in ashes were higher in this AMU compared to those of aqueous phase of normal milk at pH 6.7. ▪ This was in accordance with the literature reporting that after milk acidification at pH 4.6, the colloidal calcium phosphate is solubilized and present in the ultrafiltration permeate. ▪ Cheese values were also in agreement with those reported for semi-hard cheeses
  12. Total phosphate content ▪ Total phosphate content found in skim milk ,acid milk ultrafiltrate and in the 3 cheeses using standard colori- metric method (ISO), the ion exchange chromatography (IEC) and IEC where the acidic soaking of samples was increased (IEC+). ▪ Differences were statistically tested only within data from the same type of product; different letters refer to statistically different results P 0.05%
  13. Report Parameters Skim milk AMU cheese ISO Reference method Dry matter 94 g/kg 54.6 g/kg, 580 g/kg 90.93 total protein content 33.3 g/kg 0 245 g/kg Ashes content 33.3 g/kg 6.4 g/kg of ashes 30 g/kg 90.93 Total phosphate content 88 ± 8% 88 ± 8% 88 ± 8% 90.93
  14. Conclusion ✓ On average and across all types of milk samples, the amount of phosphate found with the IEC method was 88 ± 8% of the expected value found with the ISO ✓The loss may be due to the smaller amounts of sample used during the IEC method, hence the possibly lower representativity of heterogeneous samples as dairy products. ✓If such losses exist, both accuracy and precision could be improved simultaneously through preventing them during IEC. ✓Possibly, the correctness of the IEC method depend on the initial structure of the phosphorus in the samples. ✓If anions other than the simple orthophosphate forms were present after mineralization, e.g. polyphosphate forms, it may be that these forms could react with ammonium molybdate and hence be fully assayed by the ISO method, but not with IEC where such species would probably exhibit a different retention time than that of phosphate.