N-Nitrosamines (NAs) are potent carcinogens and have been found in food products. Herein we report a simple tandem liquid-phase extraction (TLPE) method coupled with high-performance liquid chromatography (HPLC) for the determination of trace N-nitrosamines (NAs) in food products. The TLPE method is based upon the tandem implementation of pressurized hot water extraction (PHWE) and dispersive liquid–liquid microextraction (DLLME). The target analytes were first extracted with pressurized hot water, and then concentrated into an organic phase (n-octanol) in the DLLME procedure. The TLPE-HPLC system allowed the analytes to be extracted, concentrated and analyzed in a single step with minimal manipulation of the sample preparation, with an overall analysis time of 25 min. The optimized method showed good linearity (r² ≥ 0.981) and satisfactory recoveries (74–117%) with good repeatability of the extractions (RSDs below 12.8%, n = 5). The limits of detection (LODs) for all nitrosamines in salted duck eggs were in the range of 0.08–0.55 μg kg⁻¹.

中文翻译：

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串联液相萃取与HPLC-UV在线耦合用于测定食品中的痕量N-亚硝胺†

N-亚硝胺（NAs）是强致癌物，已在食品中发现。在这里，我们报告一种简单的串联液相萃取（TLPE）方法与高效液相色谱（HPLC）结合用于食品中痕量N-亚硝胺（NAs ）的测定。TLPE方法基于加压热水萃取（PHWE）和分散液-液微萃取（DLLME）的串联实施。首先用加压热水萃取目标分析物，然后浓缩成有机相（n-辛醇）。TLPE-HPLC系统使分析物的提取，浓缩和分析只需一步即可，而对样品前处理的操作却最少，总分析时间为25分钟。优化的方法表现出良好的线性关系（- [R ² ≥0.981）和满意的回收率（74-117％）与所述提取的重复性好（相对标准偏差低于12.8％，Ñ = 5）。咸鸭蛋中所有亚硝胺的检出限（LOD）在0.08–0.55μgkg ^-1范围内。