Derivatization coupled to headspace programmed‐temperature vaporizer gas chromatography with mass spectrometry for the determination of amino acids: Application to urine samples

Abstract

A new method based on headspace programmed-temperature vaporizer gas chromatography with mass spectrometry has been developed and validated for the determination of amino acids (alanine, sarcosine, ethylglycine, valine, leucine, and proline) in human urine samples. Derivatization with ethyl chloroformate was employed successfully to determine the amino acids. The derivatization reaction conditions as well as the variables of the headspace sampling were optimized. The existence of a matrix effect was checked and the analytical characteristics of the method were determined. The limits of detection were 0.15-2.89 mg/L, and the limits of quantification were 0.46-8.67 mg/L. The instrumental repeatability was 1.6-11.5%. The quantification of the amino acids in six urine samples from healthy subjects was performed with the method developed with the one-point standard additions protocol, with norleucine as the internal standard.

Determination of Hydroxy Polycyclic Aromatic Hydrocarbons in Human Urine Using Automated Microextraction by Packed Sorbent and Gas Chromatography–Mass Spectrometry

“…As shown, there is a significant difference among the different matrices, proving the existence of matrix effect. Hence, a one-level standard addition method was proposed, which has been previously proven to be successful in eliminating the matrix effect [ 22 , 23 ].…”

Multiple headspace sampling coupled to a programmed temperature vaporizer – Gas chromatograph-mass spectrometer for the determination of polycyclic aromatic hydrocarbons in water and saliva

“…Since it was not possible to completely eliminate matrix effect, it was decided to use a one-point standard addition method for quantification of samples, which has been proved to be successful for other determinations [24,25] and it is advantageous when only small volumes of sample are available.…”