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目的建立石墨炉原子吸收光谱法和电感耦合等离子体质谱法测定虾中镉的方法并进行比较。方法样品经微波消解后,采用原子吸收光谱法和电感耦合等离子质谱法分别对河虾、明虾、沼虾的头和肌肉中镉含量进行测定,并比较两种方法的精密度和准确度。结果沼虾虾头中的镉含量高于国家标准数倍,其它虾肌肉中镉含量低于国标;两种方法测定虾中镉时,对于低含量镉,两者结果相差不大;但对于高含量时两者相差较大。原子吸收光谱法和电感耦合等离子质谱法测定同一浓度镉的精密度分别为:10.8%、2.2%,加标回收率分别为:93.5%~121.6%、99.5%~103.7%。结论原子吸收分光光度计测定镉时线性范围窄,测定高含量镉时要稀释多倍,造成结果不准确。质谱法具有抗干扰、线性范围宽、准确性好等优点,是测定虾中镉的最佳方法。
Objective To establish a method for the determination of cadmium in shrimp by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry. Methods After microwave digestion, the contents of cadmium in head and muscle of shrimp, prawn and marsh shrimp were determined by atomic absorption spectrometry and inductively coupled plasma mass spectrometry. The precision and accuracy of the two methods were compared. Results The content of cadmium in shrimp head was higher than that of national standard, while the content of cadmium in other shrimp muscles was lower than that of national standard. When the two methods were used to determine cadmium in shrimp, the difference between them was not significant for low cadmium content. Content difference between the two larger. The precision of atomic absorption spectrometry and inductively coupled plasma mass spectrometry for the determination of cadmium at the same concentration were 10.8% and 2.2%, respectively, and the recovery rates were 93.5% -121.6% and 99.5% -103.7%, respectively. Conclusion The atomic absorption spectrophotometer for the determination of cadmium linear range of narrow, when the determination of high levels of cadmium when diluted to many times, resulting in inaccurate results. Mass spectrometry has the advantages of anti-interference, wide linear range and good accuracy, which is the best method to determine cadmium in shrimp.