为提高烟丝宽度检测效率与准确性,建立了基于变径圆的烟丝宽度图像检测方法,通过与现有的ISO投影法、Hough变换法进行对比,分析了 3种方法在测量烟丝宽度时的准确性和检测效率.结果表明:①变径圆算法检测的标准线条宽度与实际宽度的相对误差最大为5％;采用变径圆法和ISO投影法测量30根烟丝,两种方法检测结果在95％置信区间内无显著性差异.②以6种烟丝样品作为实验对象,相较于Hough变换法,变径圆法测量结果更接近ISO投影法测量结果.③变径圆法检测烟丝宽度10次重复性实验相对标准偏差最大为1.2％;采用变径圆法检测6组烟丝样品宽度平均用时2.5 min,相较于ISO投影法用时的37.0 min检测效率更高,可为烟丝宽度快速检测提供支持.

本文介绍了国内8家实验室研究基于图像处理的烟丝宽度测量方法及ISO 20193:2019的精密度及检测效率.结果表明:(1)基于图像处理的烟丝宽度测量方法得到的精密度与ISO 20193:2019处于同一数量级,重复性标准差(S r)与烟丝宽度的比值小于5％,再现性标准差(S R)与烟丝宽度的比值小于8％;(2)基于图像处理的烟丝宽度测量方法比ISO 20193:2019的检测效率高.

建立了同时测定人尿液中烟碱及其9种代谢物的高效液相亲水作用色谱-串联质谱分析方法.尿液样品经乙腈和甲醇混合溶剂(体积比3:1)稀释20倍,过0.22μm滤膜后直接进样.采用Atlantis HILIC Silica柱(3.0 mm×100 mm,3.0μm),以10 mmol/L甲酸铵水溶液(用甲酸调至pH 3.0)-乙腈为流动相进行梯度分离,电喷雾正离子电离模式和多反应监测扫描模式下测定,以同位素内标法定量.结果表明,烟碱及其9种代谢物在各自的质量浓度范围内线性关系良好,相关系数(r)均大于0.997,检出限(LOD)和定量下限(LOQ)分别为0.03～0.24 ng/mL和0.10～0.80 ng/mL;在低、中和高3个加标水平下的加标回收率为81.9％～110％,日间和日内相对标准偏差(RSD)为0.50％～6.7％.该方法操作简单、灵敏度高、稳定性好,能够满足大批量人尿液中烟碱及其9种代谢物的检测需求.

Summary The width of cut tobacco strands is an important indicator for physical parameters as well as for the smoking quality. In some countries, cut width helps to distinguish fine-cut tobacco and pipe tobacco and thus differentiates taxation rate. A new method for rapid measurement of the width of cut tobacco strands was developed based on digital image processing, because the method described in ISO 20193, though easy to implement in factories, proved time consuming and generated high testing costs. The essence of this method is to determine the statistic width of incisions. The straight-line segments represent the width of strands of cut tobacco, from which the determination of the width for randomly placed tobacco strands could be achieved. Five kinds of samples (‘ISO collaborative study samples 0.4 mm, 1.0 mm, 1.6 mm and 3.0 mm’ and ‘Guangdong baked 0.9 mm’) were used to study the comparability of the measurement results between the method presented in this work and the current ISO method. Results show that accuracy and repeatability are comparable. In addition, the testing efficiency of the method presented in this work appears to be higher than the current ISO method, and it is thus a promising alternative method for measuring the width of strands of cut tobacco.

Summary Conditioning is a very important procedure for tobacco and tobacco products before their corresponding chemical and physical analysis. For cigarettes, forced air flow is generally required during the conditioning procedure. A special wind tunnel was designed to investigate how the forced air flow affects the conditioning of cigarettes in a constant climate laboratory. Two types of cigarettes with blended (including flue-cured and burley tobacco strands) and pure flue-cured tobacco strands were selected as test samples. It was found that the conditioning time to achieve the equilibrium could be shortened from 23 h without forced air flow to 7 h with a forced air flow rate of 2m/s. This is mainly due to the exchange of water molecules between cigarette samples and atmosphere being accelerated by applying the forced air flow. It was concluded that a 48 h conditioning period using the described forced air flow rate setup was unnecessary to attain the equilibrium for cigarettes. [Beitr. Tabakforsch. Int. 28 (2019) 224–229]