automatic gas chromatograph

例句：

1. 1.The automatic gas chromatograph was used to analyze the chemical composition of the sample.
   自动气相色谱仪被用来分析样品的化学成分。
2. 2.The automatic gas chromatograph was used to detect the presence of certain chemicals in the air.
   自动气相色谱仪用于检测空气中某些化学物质的存在。
3. 3.The automatic gas chromatograph was used to identify the source of the contamination in the water.
   自动气相色谱仪用于确定水中污染的来源。