在线渗析-离子色谱联用同时测定熟肉制品中的亚硝酸盐和硝酸盐

Simultaneous Determination of Nitrite and Nitrate in Cooked Meat by On-line Dialysis-ion Chromatography

采用在线渗析技术与离子色谱法联用测定熟肉制品中的亚硝酸盐和硝酸盐。样品经纯水振荡、超声提取后,离心所得的上清液过Ag柱经在线渗析后进入分离柱,采用Metrosep A Supp 4阴离子交换柱,以1.8mmol/L Na2CO3溶液与1.7mmol/L NaHCO3溶液作为淋洗液,用化学抑制型电导检测器检测。方法中NO2和NO3的检出限为0.004mg/L和0.005mg/L,样品加标回收率在88%～105%之间。该法快速、灵敏、准确,高效自动化,可同时测定熟肉制品中的亚硝酸盐和硝酸盐含量。

A new method based on the combination of on-line dialysis and ion chromatography was established for measuring nitrite and nitrate in cooked meat. Samples were suspended in water, extracted in ultrasonic bath and centrifuged. The resulted supernatant was then subjected to on-line treatment with dialysis before being injected into Ag column. Nitrite and nitrate were separated on a Metrosep A Supp 4 anion exchange column using an eluent composed of a mixed aqueous solution of 1.8 mmol/L Na2CO3 and 1.7 mmol/L NaHCO3 and monitored using suppressed conductivity detector. The limits of detection of this method for nitrite and nitrate were 0.004 mg/L and 0.005 mg/L, respectively. The average recoveries were in the range of 88%- 105%. This method presents the benefits of rapidity, high sensitivity and precision and easy performance, thereby providing a promising approach for simultaneous determination of nitrite and nitrate in cooked meat.