Method for determining lead content of feed mildew preventive

Abstract

The invention discloses a method for determining the lead content of a feed mildew preventive. According to the method, wet digestion is conducted on the feed mildew preventive by using nitric acid, hydrochloric acid and hydrofluoric acid to obtain a digestion solution, hydroboron, potassium ferricyanide, sodium hydroxide and a lead stabilizer are prepared into a lead determination reagent, the digestion solution and the lead determination reagent are carried into a chemical atomizer for hydride generation, hydride is led to an atomic absorption spectrophotometer by using carrier gas to perform flame atomization, then the absorbance value of a lead element at the position of 283.3 nm wavelength is determined, and the lead content of the feed mildew preventive is obtained through calculation based on an established standard curve. The method enables the detection limit of the lead to reach the level ppb and can achieve trace detection, and the relative error of a parallel determination result is lower than 10%, the accuracy of the detection result is good, and the detection data is more real and reliable.

Description

technical field [0001] The invention belongs to the technical field of analysis and detection of antifungal agents for feed, and in particular relates to a method for measuring lead content in antifungal agents for feed. Background technique [0002] Feed antifungal agent is a feed additive used to reduce the number of microorganisms in feed, control the metabolism and growth of microorganisms, inhibit the production of mycotoxins, prevent the loss of nutrients in feed during storage, prevent feed from mildew and deterioration, and prolong storage time. Heavy metal elements such as lead, mercury, cadmium and arsenic in feed and its additives are harmful to animals. At present, the country issued the "Feed Hygienic Standard" as early as 2001. The standard number is GB13078-2001, which is a mandatory national standard and applies to Feed and feed additive industry, including the allowable amount of lead: growing duck, laying duck, meat duck compound feed, chicken compound feed...

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Problems solved by technology

Among the above-mentioned instruments, graphite furnace detectors, polarographic analyzers and ICP-AES instruments are expensive, and the use cost of feed and feed additive enterprises is high, which is not conducive to the implementation of this method; currently it is more suitable for feed and feed additive enterprises. For hydride atomic fluorescence spectrometry, flame atomic absorption spectrometry and dithizone colorimetry

However, the pretreatment and reagent preparation of the dithizone colorimetric method are cumbersome and time-consuming; the atomic fluorescence spectrometer is currently not recognized internationally and is only applicable in China; the detection limit of the flame atomic absorption spectrometry for the determination of lead is at the ppm level , and the content of lead in antifungal agents for feed is extremely low, which can reach ppb level, so the accuracy and precision of determining the trace lead content in antifungal agents for feed by single flame atomic absorption spectrometry are poor

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