孟祥娥 王雷 郭文韬 李瑞超 胡少成 孟继荣

摘  要：本文提出了一种基于FPGA的快速气相色谱线性控温系统。该控温系统由FPGA核心控制模块、温度采集模块、PWM输出模块和网口通讯模块组成。通过增量式PID算法实现快速高精度的线性升温控制，快速升温速率可达10℃每秒，温控范围在0℃～280℃之间。将该控温系统应用于自制的快速气相色谱仪器中，快速控温精度可达±0.3℃。不同升温速率的重复性实验中，升温曲线线性部分的升温速率市值偏差小于0.1℃/s，且重复性不大于0.35%。对苯、甲苯、邻二甲苯、间二甲苯、对二甲苯组成的混合标气进行色谱分析测试，实验结果表明快速梯度升温控制可使苯系物的分离时长由15min多缩短为9min，且峰形窄、精度高，优于常规的气相色谱仪器。

关键词：气相色谱  FPGA  快速升温  线性控温系统

中图分类号：O657.7                          文献标识码：A                  文章编号：1674-098X（2021）01（a）-0031-08

Abstract：This paper proposed a fast linear temperature control system for gas chromatography based on FPGA. The temperature control system is composed of FPGA core control module， temperature acquisition module， PWM output module and network port communication module. Rapid and high-precision linear temperature rise control is realized by the incremental PID algorithm， the rapid temperature rise rate can reach 10℃ per second， and the range of the temperature control is between 0℃～280℃. The temperature control system was applied to the self-made rapid gas chromatography instrument， and the precision of the rapid temperature control was up to ±0.3℃. In the repeated experiments with different heating rates， the error of the heating rate in the linear part of the heating curve was less than 0.1℃/s， and the repeatability was no more than 0.35%. Chromatographic analysis was performed on the mixed standard gas composed of benzene， toluene， ethylbenzene and paraxylene. The experimental results showed that the separation time of 4-bell benzene series could be shortened from 5 minutes to 2 minutes by rapid gradient temperature rise control， and the peak shape was narrow and the precision was high， which was better than the conventional gas chromatographic instrument.

Key Words： Gas chromatography; FPGA; Rapid temperature rise; Linear temperature control system

在有毒有害氣体检测、大型电站现场变压器事故判断、以及环境样本的检测等领域都对快速化、小型化、便携化、高分辨率的气相色谱仪器提出了迫切需求。常规带快速程序升温的色谱仪器其检测方法复杂，操作难，时间长，体积笨重很难满足现场需求[1-4]。近年来，随着快速色谱技术的飞速发展，国外对快速色谱在现场应用已有大量报道[5-7]。通过改变色谱柱长度、减小色谱柱内径、快速程序升温、提高柱内样品流速等方法缩短物质分离时间，提高色谱分析的实时性。其中，色谱柱快速升温技术能更好的提升色谱分析速度，大幅度减小色谱仪器体积与重量，因此成为快速色谱的重要研究方向。……