目的运用串联质谱技术检测低出生体重儿氨基酸含量变化,探讨氨基酸与新生儿体重之间的关系。方法选取2014年1-12月该院新生儿疾病筛查中心接收的柳州市接产单位的510例低出生体重儿为研究组(按照不同体重分成A、B、C组),另选择同期510例正常出生体重儿为对照组。比较分析两组新生儿6种必需氨基酸的水平,探讨不同体重低出生体重儿与苯丙氨酸(Phe)、亮氨酸(Leu)、甲硫氨酸(Met)、苏氨酸(Thr)、色氨酸(Trp)、缬氨酸(Val)等6种人体必需氨基酸含量之间的关系。结果研究组Trp、Thr、Val水平明显低于对照组,Phe、Met、Leu水平明显高于对照组,两组比较差异有统计学意义(P<0.05)。A组与B组Phe、Leu、Met、Thr、Trp、Val含量比较,差异无统计学意义(P>0.05);A组与C组Phe、Leu、Met、Thr、Trp、Val含量比较,差异有统计学意义(P<0.05)。Trp、Thr、Val水平随新生儿体重增长逐渐上升,Phe、Met、Leu水平随新生儿体重增长逐渐下降。结论串联质谱检测低出生体重儿氨基酸的应用价值较高,可作为检测低出生体重儿氨基酸变化的首选方法。 Objective To detect the changes of amino acid content in low birth weight infants by tandem mass spectrometry and to explore the relationship between amino acids and body weight of neonates. Methods 510 cases of low birth weight infants received from Xinzhou Center of Neonatal Screening Center received from January to December 2014 in the hospital were selected as research groups (divided into groups A, B and C according to different body weight) Cases of normal birth weight children as control group. The levels of 6 kinds of essential amino acids in newborns of two groups were compared to explore the relationship between the levels of Phe, Leu, Met, Thr, , Trp, Val and other six essential amino acids in human body. Results The levels of Trp, Thr and Val in the study group were significantly lower than those in the control group. The levels of Phe, Met and Leu in the study group were significantly higher than those in the control group. There was significant difference between the two groups (P <0.05). The contents of Phe, Leu, Met, Thr, Trp and Val in group A and group B were not significantly different (P> 0.05) There was statistical significance (P <0.05). The level of Trp, Thr, Val gradually increased with the weight gain of neonates. The levels of Phe, Met and Leu decreased with the weight gain of neonates. Conclusions The tandem mass spectrometry (MS) detection of amino acids in low birth weight infants is of high value and can be used as the first choice for detecting the changes of amino acids in low birth weight infants.