Nitrous acid (HONO) is the major precursor of OH radicals in polluted areas. Accurate measurement of HONO provides vital evidence for exploring the formation of secondary pollution. Stripping coil (SC) equipped with ion chromatograph (IC) or spectrograph as one of wet chemical methods has been already used to measure HONO. The reliability of the method mainly depends on the collection efficiency and the interference from other species. In this study, a SC-IC method was set up to measure HONO. The performance of the method was assessed in the chamber using two kinds of absorption solutions i.e. ultrapure water and 25 μM Na₂CO₃ solution under different concentrations of SO₂. Results indicated that HONO concentrations absorbed by ultrapure water and Na₂CO₃ solution were almost identical in the absence of SO₂ in the chamber and both the collection efficiencies were >99%. However, the collection efficiency of ultrapure water decreased with the increase of SO₂, indicating that the presence of SO₂ resulted in the penetration of HONO. The collection efficiency kept >90% when the concentration of SO₂ was no >23 ppbv. Comparing with the situation without SO₂, HONO performed a remarkable increase with the presence of SO₂ when using Na₂CO₃ absorption solution, indicating that the extra generation of HONO from the reaction between SO₂ and NO₂ in alkaline solution. Consequently, ultrapure water as the absorption solution could provide a high collection efficiency and avoid the interferences from SO₂ when the concentration of SO₂ was below 23 ppbv. High correlations (slope = 0.94–1.06, r² > 0.90) were found during the intercomparisons between SC-IC and other three techniques, suggesting the SC-IC method developed in this study was able to measure atmospheric HONO in the field campaigns.

亚硝酸（HONO）是污染地区OH自由基的主要前体。HONO的准确测量为探索二次污染的形成提供了重要的证据。配备有离子色谱仪（IC）或光谱仪作为湿化学方法之一的剥离线圈（SC）已用于测量HONO。该方法的可靠性主要取决于收集效率和其他物种的干扰。在这项研究中，建立了一种SC-IC方法来测量HONO。在室内使用两种吸收溶液，即超纯水和25μMNa ₂ CO ₃溶液在不同的SO ₂浓度下评估该方法的性能。结果表明，超纯水和Na吸收的HONO浓度在腔室内不存在SO ₂的情况下，₂ CO ₃溶液几乎相同，并且两个收集效率均> 99％。然而，超纯水的收集效率与SO的增加而降低₂，表明SO存在₂导致HONO的渗透。当SO ₂的浓度不大于23 ppbv时，收集效率保持> 90％。与不使用SO ₂的情况相比，当使用Na ₂ CO ₃吸收溶液时，HONO随SO ₂的存在而显着增加，这表明SO ₂之间的反应会额外产生HONO。和碱性溶液中的NO ₂。因此，超纯水作为吸收溶液可以提供高捕集效率和避免从SO的干扰₂时SO的浓度₂低于23 ppbv的。 在SC-IC与其他三种技术的比对期间发现高度相关性（斜率= 0.94–1.06，r ² > 0.90），这表明本研究中开发的SC-IC方法能够在野战中测量大气HONO。