| Nasal feeding nutrition is a special medical formula with high amino acid content and complex composition.The composition of amino acid content can provide a method for clinically quantifying nutritional support and quality control in production,and can further improve provide reference for relevant industry production specifications.In this study,a high-performance liquid phase analysis method for 21 amino acids in nasal feeding supplements was successfully established by optimizing the conditions of fermentation and chromatographic conditions.Using phenyl isothiocyanate(PITC)as a derivatizing agent,optimizing the amount of derivatizing agent,the amount of extracting agent,the derivatization reaction time and the derivatization reaction temperature parameters.When the amount of the derivatizing agent is 1.0 mL,the amount of the extracting agent is 4.0 mL,the derivatization reaction time is 60 min,and the derivatization reaction temperature is room temperature,the amino acid derivatization effect is ideal,and the derivative remains stable within 48 h.Optimized by mobile phase,elution procedure,column,peak optimizer,column temperature and flow rate,when mobile phase A is 10 mmol/L phosphate buffer;mobile phase B is acetonitrile/methanol/ Water(45/45/10),the column is InertSil ODS-3(3.0 mm × 100 mm,3 μm),the optimizer is 0.15% triethylamine,column When the temperature is 40 °C and the flow rate is 1.0 mL/min,the ideal amino acid separation effect can be obtained within 30 min.The methodological validation showed that the linear relationship of 21 amino acids in the range of 0.01-20.0 μmol/L was good,the correlation coefficient was greater than 0.999,and the detection limit was 0.002-0.038 μmol/L.Under the three levels of high,medium and low,the method has good repeatability and good separation effect.For the pretreatment,firstly,80 mL of polyethylene glycol/ethanol solution(40/60)was used as the protein precipitant.And then the cation exchange resin method was used to separate and purify the amino acid.When the pH of the upper column was 2.5,the volume of the upper column was When the flow rate is 3 column volume/hour and the eluent is 3% ammonia water 80 mL,the recovery rate of 21 amino acids at different levels is 62.48%-82.79%,and the recovery effect is ideal.The results of nasal feeding nutritional samples showed that the amino acid content of the four groups of different sources was significantly different.Among them,CSPC Pharmaceutical Group Limited has the most abundant amino acid content;the self-prepared sample and Daisy FSMP sample have balanced amino acid content,and the product is highly targeted;EnterNutr samples have low amino acid content and unbalanced amino acid concentrations.In summary,the method for determination of 21 amino acids in nasal feeding supplements was successfully established in this study,which have the characteristics of wide linear range,good repeatability,ideal recovery rate and accurate quantitative.It can provide reference for product quality control and related standards development and update. |
