CAJ | 학술논문

基于盐酸介质中亚硝酸根对过硫酸钾氧化甲基红的褪色反应具有明显的催化作用，提出了测定痕量亚硝酸根的“NO-2-S2 O2-8-MR”新体系。结合单因素实验和正交实验建立了该新体系测定痕量亚硝酸根的最佳条件，分析了最佳实验条件下痕量亚硝酸根测定的标准曲线、检出限、精密度和抗离子干扰性能，并讨论了其反应动力学原理及参数，推导了测定痕量亚硝酸根的定量依据。研究表明，该痕量亚硝酸根测定方法的最佳实验条件为：1．0 mL 0．3 mol·L-1盐酸，1．0 mL 0．01 mol·L-1过硫酸钾，0．6 mL 0．2 g·L-1甲基红，在80℃水浴加热9 min；定量依据为：在最佳条件下，甲基红最大吸收波长518 nm 处的浓度变化 ln （A0／A）与亚硝酸根浓度呈良好线性关系，其线性范围为0．01～0．80 mg·L-1，检出限为0．007 mg·L-1；动力学特征为：亚硝酸根是一级反应，该体系符合准一级反应特征，表观活化能为85．04 kJ·mol-1，80℃时表观速率常数为0．0214 min-1，半衰期为32．39 min；动力学原理为：甲基红浓度变化ln（A0／A）与亚硝酸根浓度符合以下正比关系ln（A0／A）＝ kcNO-2；该痕量亚硝酸根测定方法尚未见报道，精密度、准确度高，选择性好，多数常见离子不干扰亚硝酸根测定，且该方法操作方便，所用试剂廉价无毒，直接用于实测食品及水样中痕量亚硝酸根含量，结果满意。
기우염산개질중아초산근대과류산갑양화갑기홍적퇴색반응구유명현적최화작용，제출료측정흔량아초산근적“NO-2-S2 O2-8-MR”신체계。결합단인소실험화정교실험건립료해신체계측정흔량아초산근적최가조건，분석료최가실험조건하흔량아초산근측정적표준곡선、검출한、정밀도화항리자간우성능，병토론료기반응동역학원리급삼수，추도료측정흔량아초산근적정량의거。연구표명，해흔량아초산근측정방법적최가실험조건위：1．0 mL 0．3 mol·L-1염산，1．0 mL 0．01 mol·L-1과류산갑，0．6 mL 0．2 g·L-1갑기홍，재80℃수욕가열9 min；정량의거위：재최가조건하，갑기홍최대흡수파장518 nm 처적농도변화 ln （A0／A）여아초산근농도정량호선성관계，기선성범위위0．01～0．80 mg·L-1，검출한위0．007 mg·L-1；동역학특정위：아초산근시일급반응，해체계부합준일급반응특정，표관활화능위85．04 kJ·mol-1，80℃시표관속솔상수위0．0214 min-1，반쇠기위32．39 min；동역학원리위：갑기홍농도변화ln（A0／A）여아초산근농도부합이하정비관계ln（A0／A）＝ kcNO-2；해흔량아초산근측정방법상미견보도，정밀도、준학도고，선택성호，다수상견리자불간우아초산근측정，차해방법조작방편，소용시제렴개무독，직접용우실측식품급수양중흔량아초산근함량，결과만의。
A catalytic kinetic spectrophotometric method for the determination of nitrite,NO2 --S2 O2-8 -MR,was developed.It is based on the fading reaction of methyl red (MR)oxidized by potassium persulfate which can be catalyzed by NO-2 in the medium of dilute HCl.The optimum experimental conditions were gained by combining single factor experiments with orthogonal experi-ments.Calibration curve,detection limit,precision,and anti-interference under the optimum experimental conditions were re-searched.Its kinetics principles and parameters were discussed.Its quantitative principle was investigated.The results show that the optimum experimental conditions of this method should be as follows:1. 0 mL 0. 3 mol·L-1 HCl,1. 0 mL 0. 01 mol· L-1 K2 S2 O8 ,0. 6 mL 0. 2 g·L-1 MR,reaction temperature 80 ℃ and reaction time 9 min.The principles for the quantitative determination of trace nitrite is that variation of MR concentration at the maximum absorption wavelength of 518 nm,ln(A0/A), shows a good linear relationship with the concentration of NO-2 under the optimum experimental conditions.Its determination range is 0. 01~0. 80 mg·L-1 and its detection limit is 0. 007 mg·L-1 .The kinetic characteristics are that the reaction order in NO-2 is 1 and the fading reaction is a pseudo first order reaction.Its apparent activation energy is 85. 04 kJ·mol-1 .Its apparent rate constant is 0. 021 4 min-1 ,and the half-life is 32. 39 min at 80 ℃.The kinetic principle is that the variation of MR concen-tration is directly proportional to the concentration of NO-2 ,ln(A0/A)= kcNO-2 .This new method for the determination of trace nitrite has never previously been reported in the published literature so far.It is highly sensitive and selective.Most of the com-mon ions don’t interfere with the determination of nitrite.This method has the advantages of convenient operation and the re-gents used are cheap and nontoxic.It was applied to the determination of trace nitrite in food and water samples with satisfactory results.