摘 要

紫菜是人们日常生活中食用较多的一种食品。它是属于广温性的海藻，普遍分布于从寒带到亚热带的潮间带水域，具有净化海洋环境、治疗甲状腺肿大的功能，具有较高的药用价值和食用价值。近几十年来随着水体的被污染，紫菜中的铬含量逐年攀升，对广大消费者的健康造成一定的威胁。

本论文的目的是通过对赣榆地区紫菜产品中的铬含量的测定，了解该地区紫菜不同生长、加工期间铬元素的变化，为企业改进生产加工工艺提供依据。

通过对赣榆地区三家紫菜养殖加工企业，不同生长期,一水到四水（一水紫菜也称头水紫菜，是指第一批次从紫菜苗上摘取的紫菜，味道鲜美，口感顺滑，营养最为丰富。接下去采集的称为二水紫菜，质量较一水来说差。三水、四水是指第三、第四次收割后的紫菜，质量远不如一水紫菜）时期的新鲜紫菜、干紫菜以及相应紫菜采捕时期的海水, 采用ICP- OES法对重金属元素铬的含量进行跟踪测定。

结果显示，新鲜紫菜中，一水时铬的最低含量为5.893mg/kg，四水时的含量最高可达20.260mg/kg。海水中铬的平均含量为10.983mg/kg，说明新鲜紫菜中的铬主要来源于海水。干紫菜中，一水时的铬含量为3.324mg/kg，为新鲜时期的一半，相应的二、三、四水时期的铬含量也是如此。说明通过企业的加工工艺，是可以除去大部分吸附在紫菜表面的铬，从而降低紫菜中的铬含量。

虽然目前来说对于干紫菜和新鲜紫菜中的铬含量没有明确的限量标准，但如此高的含量引起重视。海洋养殖业的重金属污染主要是由海洋污染引起的。随着经济发展，海洋污染越来越严重，这对海水养殖业带来很大的危害。从检测的结果也可以看出，沿海地区的海产品重金属污染程度较严重，重金属在生物体内可以高度富集，海产品中高含量的重金属对消费人群将产生较大危害，这提醒我们应将海洋环境保护放在第一位，而非一味的谋求发展。

关键词：紫菜 铬 ICP-OES 残留

Determination of chromium content in the production of seaweed in Ganyu area

Abstract

Seaweed is a kind of food that people often eat in daily life. It belongs to the eurythermic algae, widely distributed from the tropical to subtropical intertidal waters, with purifying marine environment, treatment of thyroid function,which has high medicinal value and edible value. In recent decades, with the pollution of the water body, the chromium content in seaweed is increasing year by year, which threatens the health of the vast number of consumers.

The purpose of this paper is to determine the chromium content in the products of Ganyu, and to understand the changes of chromium elements in different growth and processing, and to provide the basis for the enterprise to improve the production and processing technology.

Through the region of Ganyu three laver breeding and processing enterprises in different growth phase, a water to four water (water laver also known as head totail laver, refers to the first batch of picked from the laver seedling of seaweed, taste delicious, smooth taste, nutrition, the most abundant. The next collection called two water quality than seaweed, almost a little. Sanshui, four water refers to the third and fourth after the harvest of seaweed quality than the water laver) period of fresh seaweed, dried seaweed and seaweed harvesting period of seawater by inductively coupled plasma atomic emission spectrometry (ICP OES) tracking determination of chromium.

The results showed that the minimum content of chromium in fresh seaweed was 5.893mg/kg, while the content of four water was up to 20.260mg/kg. The mean content of chromium in seawater is 10.983mg/kg, which indicates that the chromium in fresh seaweed is mainly from sea water. In dried seaweed, the chromium content of a water is 3.324mg/kg, half of the fresh period, the corresponding two or three, four of the chromium content in the water is also the case. Through the processing technology, it is possible to remove most of the chromium adsorption on the surface of the seaweed, thereby reducing the content of chromium in the seaweed.

Although there is no clear limited standards for the chromium content of dried seaweed and fresh seaweed, but such a high level of attention. Heavy metal pollution in marine aquaculture is mainly caused by marine pollution. With the economic development, marine pollution is more and more serious, which brings great harm to the marine aquaculture industry. We can see that coastal seafood degree of heavy metal pollution was serious, heavy metals in organisms can be highly enriched and seafood in high content of heavy metals of the consumer will produce great harm, which reminds we should put the protection of the marine environment in the first place, rather than blindly seek development from the test results.

Key words: Laver ；Goiter；chromium；ICP-OES；residual

目录

摘要 I

Abstract II

第一章 绪论 1

1.1 课题背景 1

1.2 紫菜中铬的毒理学性质 1

1.2.1 铬的性质 1

1.2.2 铬的用途 2

1.2.3 铬对水体的作用 2

1.2.4 铬对人体的作用 2

1.3 铬的检测方法 3

1.4 研究内容与意义 4

第二章 实验材料与方法 5

2.1 实验材料 5

2.1.1 实验试剂 5

2.1.2 实验仪器 5

2.2 溶液的制备 5

2.3 样品预处理 6

2.4 ICP-OES工作条件优化 6

2.4.1 ICP-OES的工作条件 6

2.4.2 雾化气压力和辅助气流量的选择 6

2.4.3 分析线选择 6

2.4.4 干扰消除 7

2.4.5 测定 7

第三章 结果与分析 9

3.1 铬的标准曲线 9

3.2 实验结果 10

第四章 结论与展望 17

4.1 结论 17

4.2展望 17

参考文献 18

致谢 19

第一章 绪论

1.1 课题背景

紫菜属红藻门（Rhodophyta）、红藻纲（Rhodophyceae）、红毛菜亚纲（Bangiophycidae）红毛菜目（Bangiales）、红毛菜科（Bangiaceae）、紫菜属（Porphyra），它是人们广泛食用的一种海藻类植物。紫菜是一种生长在近海岩石上的藻类植物，含有丰富的碘元素、多种维生素及微量元素。因为紫菜中的蛋白质、铁、磷、钙、核黄素、胡萝卜素等含量居各种蔬菜之首，故紫菜又有“营养宝库”的美称。除食用的功能之外，紫菜还有很好的药理作用。例如：紫菜多糖有增强细胞免疫和体液免疫的功能，可促进淋巴细胞转化；紫菜多糖在体内外均有明显的抗凝血作用，并能显著降低血浆粘度、全血还原粘度和血细胞比容等血液流变学指标；食用紫菜多糖还能够降低血脂含量、抗肿瘤、延缓衰老。

不仅如此，紫菜也对调节海洋生态体系的平衡，净化海洋生态环境起着举足轻重的作用；同时，紫菜能释放出多种孢子，这是近海水产动物幼体和滤食动物的优质饵料。