HPLC for food analysis

... used for various purposes in modern food processing. For example, citric acid adds a fresh, acidic flavor, whereas succinic acid gives food a more salty, bitter taste. In addition to rendering foods ... Di Pietra et al., HPLC analysis of aspartame and saccharin in pharmaceutical and dietary formulations”; Chromatographia, 1990, 30, 215–219. 4. Official Methods of Analysis, Food...

Ngày tải lên: 17/04/2014, 09:12

... temperature. Food Wastes Artificial food waste was used to keep its properties constant. The composition of artificial food waste was determined based on a typical composition of food waste ... oxygen for the solubilization of food waste. The circulating water did not contain oxygen when aeration was not carried out in the circulation tank. Therefore, oxygen would be defic...

Ngày tải lên: 05/09/2013, 08:40

Ngày tải lên: 09/12/2013, 18:15

... the most widely used systems for analysis of large bio- molecules. For a continuous ion source, the ions can be stored for a short period of time and pulsed out for analysis. In the case of ESI, ... isomer differenti- ation, protein sequencing, and mixture analysis. MS/MS experiments are often performed in combination with HPLC for analysis of complex mixtures. 7.4 ROLE OF I...

Ngày tải lên: 15/12/2013, 12:15

... 102]. The use of MRM methods for quantitative bioanalysis often reduces sample preparation and analysis time. The MRM method that used LC/ESI-MS/MS for the quantitative analysis of an anticancer ... metabolites are important biotransformation pathways for many drugs and xenobiotics [127, 132, 133]. For example, the formation of acyl glucuronide conjugate forced the withdrawal of f...

Ngày tải lên: 15/12/2013, 12:15

... very important to understand the aim of analysis and the requirements for a par- ticular method to be developed. The aim of analysis of each HPLC method may vary for each developmental area in the ... the ACD prediction of the solubil- ity for the ionized form of bases and acids shows greater deviation than for the solubility predicted for the neutral form of the molecules. Re...

Ngày tải lên: 15/12/2013, 12:15

... in their ionic form or neutral form. This may be dependent on the type of analysis that is required. If fast analysis is required, then analysis of the component in its ionized form may be acceptable ... by the pressure limitation of the HPLC equipment. For more information on gradient separation and developing fast HPLC methods, see Chapter 17 and Practical HPLC Method Developm...

Ngày tải lên: 15/12/2013, 12:15

... The experiments for w w pH 2–4 were performed on day 1, and those for w w pH 5–7 were performed on day 2 (≈36 hr after initial prepa- ration).A further investigation was performed by preparing ... height) for peak B ≤ 1.5 • Tailing factor (5% peak height) for peak A ≤ 1.5 • Rt for peak A must be 12.0 ± 1.3 min • Rt for peak B must be 21 ± 1.0 min • The S/N of the LOQ solution (0...

Ngày tải lên: 15/12/2013, 12:15

... Figure 8-40A for the sample stored in the acidic diluent for 4 days at room temperature shows some degradation compared to Figure 8-40B for the sample stored in the acidic diluent for one day ... analyte pK a shift) for both basic ionization centers. Therefore this cor- relates with a s s pK a of 2.7 for pyridinal nitrogen (i.e., 3.3 − 0.6 = 2.7) and with a s s pK a of 4.7 for...

Ngày tải lên: 15/12/2013, 12:15

... that was optimized by Drylab, a forced degrada- tion sample was run that was stressed at 50°C for 1 week in pH 1 diluent. It was noted that a major impurity was formed (Figure 8-49) and was determined to ... isocratic conditions for deter- mining the most suitable pH for the method. The retention behavior of active as a function of pH (isocratic) was determined. The best mobile-phase pH...

Ngày tải lên: 15/12/2013, 12:15