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环氧树脂是一种热固性高分子聚合物,通常为环氧氯丙烷与双酚A或多元醇的缩聚产物. 因其具有良好的绝缘性、耐腐蚀性、密封性和高黏结强度等性能[1-3],作为涂料、胶黏剂、浇铸料等已广泛应用于电器、电机和电子元器件中[4-5]. 有机含卤化合物(主要是有机氯化物和有机溴化物)已作为阻燃剂广泛应用于各种塑料制品、玩具和电子产品中,是目前应用最为广泛的一类阻燃剂[6]. 含卤化合物在燃烧过程中产生的有毒酸性气体会对人的呼吸系统造成影响;废弃的聚合物因不完全燃烧会产生强致癌性的二噁英类物质,而二噁英具有高富集性和迁移性,且难以降解,属于持久性有机污染物(POPs),对环境和人体的健康均会构成潜在危害[7-8]. 卤素的限制和控制使用成为世界各国的共识,同时也促进了“无卤素”材料的推广应用. 欧盟于2006年实施了《关于在电子电气设备中限制使用某种危险物的指令》(RoHS指令),对用于阻燃剂的多溴联苯和多溴联苯醚进行了限量使用的规定[9];国际电工技术委员会颁布了EN61249-2-21限量标准,对电子产品材料、玩具中卤素的含量进行了明确的规定:氯和溴的含量均不超过900 mg· kg−1,溴和氯总量不超过1500 mg· kg−1 [7,10],符合要求的材料称为“无卤素”材料. 因此准确测定相关产品和元器件中的卤素对于产品出口和质量检测具有非常重要的意义.
离子色谱法是一种快速准确的卤素测定方法,而聚合物中卤素不能直接进行测定,需要通过一定的前处理手段将其转化为无机阴离子. 最常见的聚合物中卤素的前处理方法有氧弹燃烧法[3,6-8,11-14]和高温燃烧裂解法[15],氧弹燃烧法是在密闭容器(氧弹)中充入高压氧气,经点燃后将聚合物进行燃烧分解,样品中卤素转化为卤化氢,被吸收液吸收后进行离子色谱的测定. 与早期的氧瓶燃烧法相比,氧弹燃烧法能够使样品燃烧更完全,样品的燃烧损失小,不容易受到污染,操作过程安全可靠. 但该方法自动化程度低,样品测定周期长,燃烧后卤素离子容易吸附在氧弹装置内壁及点火线上,需要仔细冲洗. 高温燃烧裂解法是采用一种高温燃烧裂解炉及吸收装置,将样品通过石英舟推入到裂解炉的石英管中,在氧气和水蒸气的混合气流中进行高温氧化燃烧、裂解及气化,同时进行水蒸气吸收并通过吸收瓶收集冷凝液,将聚合物中的氯、溴等卤素转化为阴离子,将吸收液直接导入离子色谱仪即可实现聚合物中卤素的快速测定. 该方法操作简单、灵敏度高、可实现与离子色谱的联用,已用于植物油[16]、纺织品[17]、炭黑[18]和水泥[19]中氟、氯、溴等的测定,但对于环氧树脂中氯和溴的同时测定未见报道.
本研究采用高温燃烧裂解法进行环氧树脂的样品前处理,对影响高温燃烧裂解参数进行了选择优化,通过与离子色谱的在线联用实现环氧树脂中氯和溴的快速测定,并与传统的氧弹燃烧-离子色谱法进行了比较和方法确认. 该方法将自动化的高温燃烧裂解与配备预浓缩柱的离子色谱相结合,进一步降低了氯和溴的检出限,操作简单,准确度高,可用于相关产品的快速检测和批量产品的质量控制.
在线燃烧离子色谱法测定环氧树脂中的氯和溴
Determination of chlorine and bromine in epoxy resins by online combustion ion chromatography
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摘要: 建立了在线燃烧离子色谱同时测定环氧树脂中氯和溴的分析方法. 采用高温裂解炉与离子色谱的在线联用装置,通过对样品进行高温燃烧裂解和气化,以100 mg·L−1过氧化氢为吸收液,将产生的卤化氢气体吸收并转化为无机阴离子,离子色谱法进行样品的测定,以氯和溴的峰面积外标法进行定量. 对影响燃烧效果和测定结果准确度的因素如燃烧时间、燃烧温度、吸收液体积、称样量、氧气和氩气流速等条件进行了选择优化. 在(0.10—2.50)mg·L−1和(0.02—0.50)mg·L−1范围内,氯和溴离子的线性相关系数(r2)大于0.999,该方法对于氯和溴的定量下限分别为0.55 mg·kg−1和2.60 mg·kg−1. 采用建立的方法分别对环氧树脂和EC680k低密度聚乙烯标准物质中的氯和溴进行测定,并与传统的氧弹燃烧-离子色谱法进行了比较. 结果表明:在线燃烧离子色谱法对于环氧树脂中氯和溴测定结果的相对标准偏差分别为1.28% 和2.29%,测定值与氧弹燃烧-离子色谱法基本一致,EC680k的测定结果与标准值符合,证明该方法具有良好的准确度和精密度. 该方法准确度和灵敏度高、重复性较好,能够满足批量树脂类样品中氯和溴的含量筛查和多批次产品的质量控制.Abstract: A method for the simultaneous determination of chlorine and bromine in epoxy resins by online combustion ion chromatography was developed. High-temperature pyrolysis furnace coupled with ion chromatography was used to decompose and gasify the samples at high temperature, and hydrogen peroxide (100 mg·L−1) was used as absorbent. The resulting hydrogen halide gas was absorbed and transformed into inorganic halogen anions, and the samples were separated and determined by ion chromatography, which was quantified by an external standard method using the peak area of chlorine and bromine. Parameters that affect the combustion effect and the accuracy of the results such as combustion time, combustion temperature, the volume of the absorption liquid, sample weight, and the flow rate of oxygen and argon were optimized. In the range of (0.10—2.50) mg·L−1 and (0.02—0.50) mg·L−1, the linear correlation coefficient (r2) of chlorine and bromine was greater than 0.999. The limits of quantitation of this method for chlorine and bromine was 0.55 mg·kg−1 and 2.60 mg·kg−1, respectively. Chlorine and bromine in epoxy resins and EC680k low-density polyethylene certified reference materials were determined by the established method, and the results were compared with the traditional oxygen bomb combustion-ion chromatography. The results showed that the relative standard deviations of chlorine and bromine in epoxy resins were 1.28% and 2.29%, respectively, which were consistent with the results of oxygen bomb combustion-ion chromatography, the determination results of EC680k wee in accordance with the certified value, which proves that the method has good accuracy and precision. The method has high accuracy, sensitivity and repeatability, and can meet the requirements of screening chlorine and bromine content in batch samples and quality control of multi-batch products.
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Key words:
- online combustion ion chromatography /
- epoxy resins /
- chlorine /
- bromine
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表 1 氯和溴离子的保留时间、线性、检出限和定量下限(mg·L−1)
Table 1. Retention time, linearity, detection limits (LOD) and quantitation limits (LOQ) of chlorine and bromine (mg·L−1)
分析物
Analyte保留时间/min
Retention time线性方程
Regression equation线性相关系数r2 线性范围
Linear rangeLOD LOQ Cl 5.94 y=0.4160+0.0137x 0.9999 0.10—2.50 2.64 8.83 Br 8.54 y=0.0120+0.0047x 0.9992 0.02—0.50 2.34 7.80 表 2 样品测定结果 (mg· kg−1,n=6)
Table 2. Results of the samples (mg· kg−1, n=6)
测定结果
Analyte在线燃烧离子色谱法
Online combustion-ion chromatography氧弹燃烧-离子色谱法
Oxygen bomb combustion-ion chromatography氯 溴 氯 溴 1 4301 482 4332 493 2 4352 465 4357 505 3 4235 471 4341 512 4 4273 490 4356 511 5 4341 492 4222 511 6 4218 488 4303 510 平均值 4287 481 4319 507 RSD /% 1.28 2.29 1.19 1.44 -
[1] BUCKNALL C B, GILBERT A H. Toughening tetrafunctional epoxy resins using polyetherimide [J]. Polymer, 1989, 30(2): 213-217. doi: 10.1016/0032-3861(89)90107-9 [2] FANG C, GUAN D B, YAO W G, et al. Studies on mechanical and thermal properties of epoxy resin modified by fluorine-containing silicone [J]. Applied Mechanics and Materials, 2013, 401/402/403: 713-716. [3] 汪丽, 余小岚, 黄滨, 等. 氧弹燃烧法测定环氧树脂中氮含量 [J]. 中山大学学报(自然科学版), 2009, 48(3): 139-141. WANG L, YU X L, HUANG B, et al. Determination of nitrogen contents of epoxy resins by oxygen bomb combustion and oxygen bottle combustion [J]. Acta Scientiarum Naturalium Universitatis Sunyatseni, 2009, 48(3): 139-141(in Chinese).
[4] 范亚平, 任天斌, 黄艳霞, 等. 水性环氧树脂涂料及其固化机理的研究 [J]. 涂料工业, 2006, 36(7): 17-21. FAN Y P, REN T B, HUANG Y X, et al. Study on waterborne epoxy resin coatings and its curing mechanism [J]. Paint & Coatings Industry, 2006, 36(7): 17-21(in Chinese).
[5] 马明, 闵红, 周宇艳, 等. 顶空-气相色谱-负化学离子源质谱法测定水性环氧树脂涂料中表氯醇 [J]. 环境化学, 2015, 34(5): 1017-1019. MA M, MIN H, ZHOU Y Y, et al. Determination of epichlorohydrin in waterborne epoxy resin coatings by headspace-gas chromatography-negative chemical ion source mass spectrometry [J]. Environmental Chemistry, 2015, 34(5): 1017-1019(in Chinese).
[6] 巩东侠, 刘肖, 江海飞, 等. 氧弹燃烧-离子色谱法测定电子元器件中的卤素 [J]. 岩矿测试, 2009, 28(6): 545-548. GONG D X, LIU X, JIANG H F, et al. Determination of halogen in electronic components by oxygen bomb-ion chromatography [J]. Rock and Mineral Analysis, 2009, 28(6): 545-548(in Chinese).
[7] ZHANG S, ZHAO T B, WANG J, et al. Determination of fluorine, chlorine and bromine in household products by means of oxygen bomb combustion and ion chromatography [J]. Journal of Chromatographic Science, 2013, 51: 65-69. doi: 10.1093/chromsci/bms108 [8] 童国璋, 徐哲明. 氧弹燃烧-离子色谱法测定高分子聚合物的卤素[J]. 环境科学与技术, 2011, 34(增刊1): 268-270. TONG G Z, XU Z M. Determination of halogen in the polymer by ion chromatography with oxygen bomb combustion[J]. Environmental Science & Technology, 2011, 34 (Sup 1): 268-270(in Chinese).
[9] The European Parliament and the Council of the European Union. Directive 2002/95/EC: on the restriction of the use of certain hazardous substances in electrical and electronic equipment[R]. 2003. [10] International Electrotechnical Commission. Reinforced base materials, clad and unclad non-halogenated epoxide woven E-glass reinforced laminated sheets of defined flammability (vertical burning test), copper-clad[R]. 2003. [11] 何晓俊, 刘奇祥, 庞承焕, 等. 离子色谱法测定塑料中卤素准确性研究 [J]. 现代塑料加工应用, 2021, 33(6): 32-34. HE X J, LIU Q X, PANG C H, et al. Study on accuracy of ion chromatography for determination of halogens in plastics [J]. Modern Plastics Processing and Applications, 2021, 33(6): 32-34(in Chinese).
[12] 马志斌, 王淑杰, 张磊. 氧弹燃烧-离子色谱法测定电子产品中的卤素 [J]. 分析仪器, 2012(6): 36-38. MA Z B, WANG S J, ZHANG L. Determination of halogen in electric products by ion chromatography [J]. Analytical Instrumentation, 2012(6): 36-38(in Chinese).
[13] 涂建国, 司亚春. 氧弹燃烧-离子色谱法测定电子电气产品中卤素[J]. 化学分析计量, 2014, 23(增刊1): 29-31. TU J G, SI Y C. Determination of halogen in electrical and electronic products by oxygen bomb–ion chromatography[J]. Chemical Analysis and Meterage, 2014, 23(Sup 1): 29-31(in Chinese).
[14] 叶晨, 曾文法, 杨俊明. 氧弹燃烧-离子色谱法测定塑胶中卤素 [J]. 广州化工, 2013, 41(8): 136-138,220. doi: 10.3969/j.issn.1001-9677.2013.08.051 YE C, ZENG W F, YANG J M. Determination of halogen in plastic by oxygen bomb-ion chromatography [J]. Guangzhou Chemical Industry, 2013, 41(8): 136-138,220(in Chinese). doi: 10.3969/j.issn.1001-9677.2013.08.051
[15] 高欢, 卫碧文, 杨荣静等. 自动裂解-离子色谱联用技术测定电子电气产品中卤素和硫 [J]. 环境化学, 2011, 30(5): 1051-1052. GAO H, WEI B W, YANG R J, et al. Determination of halogen and sulfur in electronic and electrical products by automatic pyrolysis-ion chromatography [J]. Environmental Chemistry, 2011, 30(5): 1051-1052(in Chinese).
[16] CHIVARZIN M E, REVELSKYN I A, NIKOSHINA A V, et al. New approach to the fast screening of plant oil samples for F-, Cl-, Br- and S-organic compounds on the trace level [J]. Talanta, 2016, 150: 113-117. doi: 10.1016/j.talanta.2015.12.002 [17] 曹丽华, 丁友超, 张秀等. 高温燃烧-水蒸气吸收-离子色谱法测定纺织品中的有机卤化物 [J]. 分析测试学报, 2022, 41(2): 234-241. CAO L H, DING Y C, ZHANG X, et al. Determination of organic halides in textiles by ion chromatography method with high temperature combustion and water vapor absorption [J]. Journal of Instrumental Analysis, 2022, 41(2): 234-241(in Chinese).
[18] 梁晨, 张锦梅, 郑秀瑾等. 在线燃烧-离子色谱法测定炭黑中氯和溴的含量 [J]. 理化检验-化学分册, 2019, 55(11): 1345-1348. LIANG C, ZHANG J M, ZHENG X J, et al. IC determination of chlorine and bromine in carbon black with on-line combustion [J]. Physical Testing and Chemical Analysis (Part B:Chemical Analysis), 2019, 55(11): 1345-1348(in Chinese).
[19] 王碗, 刘肖, 蔡亚岐, 等. 自动快速燃烧炉-离子色谱联用技术检测水泥等建材中的氯 [J]. 分析试验室, 2007, 26(12): 10-13. doi: 10.3969/j.issn.1000-0720.2007.12.003 WANG W, LIU X, CAI Y Q, et al. Determination of chloride in some building materials by automatic quick furnace-ion chromatography [J]. Chinese Journal of Analysis Laboratory, 2007, 26(12): 10-13(in Chinese). doi: 10.3969/j.issn.1000-0720.2007.12.003