Problems that are easily overlooked in quality control work

1. The raw material samples to be tested should be representative. Therefore, it is recommended that the sampling points of each batch of raw materials be as many as possible, and the number of samples should be as much as possible (because adulteration is not only present in the same bag of raw materials, but also in different bag raw materials). I experienced: in a batch of flour, the package around the car is qualified flour, the middle part is a non-conforming product with 50% bran; in a batch of calcium hydrogen phosphate, more than 10 packets of color are gray, the calcium content is high. Insufficient phosphorus content is suspected to be a non-conforming product of stone powder. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

2, when the raw material microscopy, often just a simple look, and did not do the appropriate treatment. It is recommended to combine some treatment methods before microscopy to detect more adulterants. Specific practices are: EEd China Feed Industry Information Network - based on feed, serving animal husbandry

(1) Screening: The sample is sieved by standard sieves of different size holes, and samples of different sizes can be screened for targeted microscopic examination. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

(2) Carbon tetrachloride treatment: Samples with high oil content or a large amount of particles adhered to it can be treated with carbon tetrachloride solution (fish meal, meat and bone meal and most poultry feed and unknown feed are best used in this method). This allows the use of different density principles to separate light-weight floats (generally adulterated in floating objects) and heavy-density materials. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

(3) Acetone treatment: The ability to dissolve organic matter and dehydration by acetone is used to treat samples with a mass structure formed by molasses or high ambiguity, and the sample can be observed more clearly. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

For the suspected samples of microscopic examination, I do not know how to use some simple chemical reactions to qualitative analysis (such as dilute hydrochloric acid method, iodine-potassium iodide staining, phloroglucin staining, etc.), but blindly determine. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

3, over-reliance on laboratory testing indicators, not sensitive to sensory testing. Some raw materials can only distinguish between true and false by sensory inspection. It is not necessary to send them to the test (such as a lot of bran in the flour, sour and sour in the soybean meal), and it is a taboo for quality control without thinking about mechanically. EEd China Feed Industry Information Network - based on feed, serving animal husbandry

Author: Wuhan Fanhua Biological EEd China Feed Industry Information Network - based feed, animal husbandry services