【求助】求助 谁能帮我把这篇关于 《果汁中硝酸盐、亚硝酸盐的测定 》 的英文文章整理一下？非常感谢

Determination of Nitrite and Nitrate in Fruit Juices by UV Detection
用紫外检测仪来测定水果汁中的硝酸盐和亚硝酸盐
S. Marten, J. Harms, Wissenschaftliche Gerätebau Dr. Ing. H. Knauer GmbH
Introduction:
引言:
A method for the determination of nitrite and nitrate in parallel by UV detection is described.
描述了一个使用紫外检测仪来平行检测硝酸盐和亚硝酸盐的方法
Simultaneous determination of nitrite and nitrate is proposed for monitoring
threshold levels of these additives in foods.
建议采用同步监测硝酸盐和亚硝酸盐的方法来监控食品中这些添加剂的临界值
The acute toxicity of nitrate is in this instance of only peripheral importance.
硝酸盐的急性毒性在这里不显得那么重要了。
The primary health hazard lies rather in the rapid reduction of nitrate to nitrite
which leads to the production of carcinogenic nitrosamine when nitrite reacts with
secondary amines in the stomach.
最严重的健康危害是在硝酸盐还原为亚硝酸盐时，亚硝酸盐在胃中与二级胺反应而导致的致癌性亚硝胺的产生。
In addition, nitrite is also known to cause methemoglobinemia (oxygen deficiency) to occur in 另外,亚硝酸盐也是已知造成血红蛋白血症(氧气不足)发生婴儿.
infants.
另外，总所周知，亚硝酸盐也会对婴幼儿造成高铁血红蛋白症（(氧气不足)
In order to provide a way to monitor the legal recommended limits of these additives in foods, a rapid and cost-effective HPLC method is presented here.
为了提供一个监控这些食品添加剂的法定推荐限量的方法，本文介绍了一个快速而经济的高效液相色谱方法。
With an isocratic Smartline HPLC system from Knauer, one can carry out an
uncomplicated and fast analysis.
利用Knauer公司的等度Smartline高效液相色谱系统，便可以进行一个简单而快速的分析。
The analysis of nitrite and nitrate in fruit juices can be carried by ion pair chromatography on Knauer RP C18 phases using various counter ions (n-octylammonium or tetrabutylammonium).
果汁中亚硝酸盐和硝酸盐的检测可以通过离子对色谱，利用各种反离子（四辛基胺或四丁基胺）在Knauer RP C18相上进行测定
The detection takes place by UV at 210 nm.
紫外检测波长为210纳米
The Smartline system used consists of the Pump 1000, the UV Detector 2500, the Autosampler 3800, the Manager 5000 with degasser unit and the Column Oven 4000.
此Smartline系统组成为: 泵1000, 紫外检测器2500， 自动进样器3800， 带有脱气装置的管理器5000， 柱箱4000。
（这些数字不是价格吧）
HPLC method parameters:
HPLC参数
Column: Eurosil Bioselect 300-5 C18, 120 x 4 mm (I7Y413) [or Eurospher 100-5 C18, 250 x 4.6 mm (I115Y535)]
色谱柱: Eurosil Bioselect 300-5 C18, 120 x 4 mm (I7Y413) [or Eurospher 100-5 C18, 250 x 4.6 mm (I115Y535)]
洗脱液: 0.01 M n-octylamine, set to pH 4 / 5 mM
[or tetrabutylammonium hydrogen sulfate set to pH 6.5] （ 或硫酸氢四丁基铵， pH值6.5）
Flow: 1 ml/min
流速：1 ml/min
Temperature: 30 °C [40 °C]
温度：30 °C [40 °C]
Injection volume: 5 μl
进样量：5 μl
Detection: UV (Smartline 2500) at 210 nm
紫外检测波长：(Smartline 2500) 210 nm
Sample preparation:
样品制备：
Carrez solution: Solution of potassium hexacyanoferrate (II) in water, p.A.
c = 150 g/L
Carrez 溶液I ：亚铁氰化钾 （II）的水溶液， 浓度约150 g/L （p.A什么意思）
Carrez solution II: Solution of zinc sulfate in water, p.A., c = 300 g/L
Carrez 溶液II: 硫酸锌水溶液， 浓度约300 g/L
SPE method: condition SAX cartridges with 2 ml MeOH and 4 ml water, load 1 ml sample, wash with 3 x 1 ml water, elute with 2 ml
0.5 M NaCl solution
固相萃取方法：用2毫升甲醇和4毫升水洗涤SAX 柱，装入1毫升样品，1毫升的水洗三次，2毫升氯化钠(0.5M)溶液洗提。
Calibration solutions were prepared from nitrite and nitrate standards in the range of 0.1 ppm to 25 ppm.
使用硝酸盐和亚硝酸盐标样来制备浓度范围为0.1ppm 到25ppm的校准溶液
For nitrate, the concentration range was extended to 200 ppm. Commercially available fruit and vegetable juices were investigated after treatment with the Carrez I and II solutions in a ratio of 50:1.
对硝酸盐,浓度范围扩大到200ppm. 商品水果和蔬菜汁在使用比率为50：1的Carrez I 溶液和Carrez II溶液后处理进行检测。
Once precipitated, the sample was centrifuged and the supernatant was removed. In order to remove potentially interfering substances, the sample can be further cleaned on an SPE anion exchange cartridge. The filtrate can then be used directly for HPLC analysis.
如有沉淀， 离心样品， 出去上层漂浮物。为了消除潜在的干扰物质， 可在一个SPE阴离子交换柱上进一步清洗样品。滤液可直接用于高效液相色谱分析.
Results: Since both ions are typically present in markedly different concentrations, their simultaneous determination using a conductivity detector under a set sensitivity range is not always possible.
结果: 因一般来说两种离子的浓度差别很大， 在一个设定的条件下使用电导检测器来同步测定此两种离子，常常都不能成功。


Herein lies the strength of this method with ion pair chromatography and UV detection. With this technique, both ions can be detected down to a concentration of 0.1 ppm.
因此提出了使用离子对色谱和紫外检测器来进行检测的方法。通过此项技术，此两种离子都可以进行检测，且检测的浓度可以低至0.1ppm.
This value represents the limit of quantitation for both ions.
此值代表此两种离子的量检测限。
The use of two different ion pair compounds as eluents allows for adjustment of
coeluting peaks and ensures reliable results. Linear calibration curves for the standards run with both eluents showed regression coefficients (r2) of 0.9998 or better.
使用两种不同的离子对化合物作为洗脱液允许调整重叠峰并可保证可信的结果. 使用两种洗脱液做出的线性校准曲线的回归系数（r2）为0.9998甚至更好。
The recovery rate of both ions is not influenced by the Carrez precipitation procedure: 95 –98 %, without the SPE step.
未经SPE步骤，两种离子的回收率均没有受到Carrez析出过程的影响:95-98%。
Inclusion of the SPE step only reduces the recovery rate slightly, however the
sensitivity is reduced by a factor of 2 through dilution in the elution step (1 ml loaded sample / 2 ml extraction volume).
加入SPE 步骤只稍稍地降低了回收率，但是灵敏度在洗提步骤（1毫升加入的样品对2毫升萃取体积）被一个2的因素降低了。
As had been expected, nitrite ion concentrations below the 0.1 ppm limit of quantitation were found in the fruit and vegetable juices examined.
正如所预见的， 在水果和蔬菜汁检测到了低于0.1ppm量限的亚硝酸盐离子浓度
Manufacturers of such juices must not allow nitrite concentrations to exceed 0.1 ppm in their products.
生产这些果汁的生产厂家必须控制他们的产品中亚硝酸盐的浓度不能超过0.1ppm.
Nitrate values varied widely among the vegetable juices tested. While the nitrate value for one brand of carrot juice was 140 ppm, another brand of red beet juice gave a nitrate value of approximately 850 ppm, well outside of the calibration range.
硝酸盐的浓度在检测的蔬菜汁差别很大。一个品牌的胡萝卜汁中硝酸盐的浓度为140ppm, 而另外一个牌子的红甜菜汁中硝酸盐的含量大约为850ppm, 都远远超过了标准范围。