ABSTRACT
BACKGROUND: At present, in the quality control file or technical standards of in vitro fertilization medium, indicators for component contents and detection methods have not yet been defined. To ensure the safety and effectiveness of these products, we should try to establish and improve the quality standards. OBJECTIVE: To establish a method for simultaneously testing 18 kinds of amino acids by ultra-high performance liquid chromatography-tandem mass-spectrometry (UHPLC-MSMS), and to analyze the difference in the content of different amino acids in the medium for different uses. METHODS: Using the UHPLC-MSMS, we detected the indicator components of 18 different amino acids in the in vitro fertilization medium. These amino acids included glycine, leucine, methionine, tyrosine, histidine, threonine, alanine, isoleucine, tryptophan, cystine, lysine, aspartic acid, valine, phenylalanine, valine, serine, glutamic acid, arginine. The UHPLC separation was performed on a SUPELCO Discovery HS F5-3 column (15 cm×2.1 mm, 3 μm) in a gradient elute mode with acetonitrile and water (both containing 0.1% formic acid) as the mobile phase at a flow rate of 0.35 mL/min. The column temperature was 40 ℃. MS detection was performed with multiple-reaction monitoring mode using negative electro spray ionization. RESULTS AND CONCLUSION: The linearity was achieved in the range of 0.25-12.5 mmol/L for the 18 different amino acids. The average recovery rate of these amino acids ranged 86.3% to 125.3%. The relative standard deviation of the precision experiment and the repeatability experiment was less than 4.7%. These findings indicate that this is a sensitive, rapid, accurate, and specific method that can be used for the quality control of in vitro fertilization medium.
ABSTRACT
BACKGROUND:In the current quality control file or technical standards of the hemodialysis catheter,the indicators of the component contents and detection methods of the residual diphenylmethane diisocyanate (MDI) monomer are undefined.To ensure the safety and effectiveness of these products,we should try to establish and improve the quality standards.OBJECTIVE:To establish a method for determination of the residual MDI monomer in a hemodialysis catheter by gas chromatography (GC),and to analyze the bio-security of the MDI.METHODS:Samples collected in the hemodialysis catheter were heated to reflux with ethyl acetate and the residual MDI content was analyzed by the GC.The GC separation was performed on a DB-5 MS column (30 mx0.25 mm),the temperature of which rose by program.The initial temperature was 60 ℃,maintained for 5 minutes,rose to 280 ℃ with a rate of 15 ℃/min,and maintained for 6 minutes.The temperature of the Injector and FID detector was both 280 ℃.Carrier gas was 99.999％ nitrogen.RESULTS AND CONCLUSION:The linearity was achieved in the range of 4.970-99.40 mg/L (r=0.999 64) for MDI.The mean recovery rate was 100.9％ with the relative standard deviation of 3.2％ (n=6).The residue of MDI monomer in the three batches of samples was lower than the tolerable exposure.Therefore,it is a sensitive,rapid,accurate,specific method that can be used for the quality control of the residual MDI monomer in the hemodialysis catheter.