it is difficult to digest
Some time ago, the media has reported a message of "crab tomatoes with fresh produce arsenic", sparked heated debate. Agree with this view, most people think that vitamin C can pentavalent arsenic contained crabs, transformed into trivalent arsenic, and arsenic to form similar toxins.
This view correct? Recently, the Modern Express reporter came to the physical and chemical testing center in Jiangsu Province, together with the relevant experts, the use of professional equipment, carry out the experiment.
Modern Express reporter Zhu Pei Hao more
News Background
"Crabs not only can not eat together with tomatoes, but all the ingredients contain vitamin C (Vc) are not fit to eat with crab together, otherwise the consequences will be very serious." Heilongjiang a dermatologist Wei Juan explanation is given, the crabs are crustaceans organisms containing pentavalent arsenic, no harm to the human body itself, but in the role of vitamin C, will become trivalent arsenic compounds,giubbotti woolrich, that is, people said arsenic.
Phoenix Palace Harbin crab crabs further suggested that: try not to eat crab with tomatoes, cold drinks, tea, peanut, will produce some allergy symptoms.
For this argument, the experts argue: Impossible
China Agricultural University, FAN Zhi food safety experts openly questioned, "If the crab in the arsenic is not exceeded a few times, it is impossible to poisoning." She said that the rumor has been circulating for a long time,http://llo3ll.s35.xrea.com/yza-dou/88club/apeboard_plus.cgi/apeboard_plus.cgi?command=read_message&msgnum=740/, "We spent a few years to the rumor, but still Jiabu Zhu Rumors continue. "
Food safety experts Zhu Yi also microblogging commented: "In the lab, vitamin C has the potential to pentavalent arsenic into highly toxic trivalent arsenic,http://www.bbrenjia.com/forum.php?mod=viewthread&tid=6192, but not easy in the diet."
There were more bluntly: two elements together is not able to generate a third element, which is not "1 + 1 = 2" chemistry experiments.
Principle
Although the "trivalent arsenic" and "Arsenic" is inorganic arsenic, "two brothers" a toxic and a non-toxic. Rumors, vitamin C, and crabs with food, can be toxic pentavalent arsenic is converted to toxic trivalent arsenic, and trivalent arsenic if it reaches a certain amount of damage to the human body is not small.
Whether it really will lead to the conversion of vitamin C? Modern Express reporter idealized simulated by laboratory experiments, solved the mystery.
Inorganic arsenic extracted from shrimp and crab, the solution may contain other substances, so this experiment configuration chosen solution arsenic. Among them, the arsenic limit is calculated in accordance with the national marine crabs inorganic arsenic standard (0.5 milligrams per kilogram). That is, if taking one gram of fresh crabs, wherein the content of inorganic arsenic may not exceed a maximum of 0.0005 mg.
Experimenter preparation 50 ml of a solution containing 0.0005 mg of inorganic arsenic. Considering the crabs and the foods containing vitamin C,moncler piumini, ultimately into the stomach,http://www.d9sj.com/thread-418029-1-1.html, hydrochloric acid and gastric juice, will also affect the reaction takes place. In several experimental control group, the portion of the solution by adding a certain concentration of hydrochloric acid.
Physical and chemical testing center experts and reporters together, the experimental group were tested 11 samples, equipment testing using a dual channel atomic fluorescence spectrometer. This instrument can easily measure the concentration of toxic trivalent arsenic, and the data presented on the computer. The results in the following table
No. Description solution of hydrochloric acid was added Vc pentavalent arsenic concentration measured conversion rates
Volume Vc volume concentration concentration (%) of trivalent arsenic (%)
(Ml) (μg / L) (%) (g) concentration
(Μg / L)
An acid-free Vc 50 10 None None None None 0.49 4,scarpe nike air max.9
2 0.3% acid-free Vc 50 10 0.3 0.70 7.0 No No
35% acid-free Vc 50 10 5 31,http://www.prco.jp/~shake/apeboard/apeboard_plus.cgi?command=viewres&target=96988/.7 3.17 None None
4 0.033% Vc acid-50100 0.016 0,http://disqo.captainhirafu.com.033 0.45 4.5
5 0.075% Vc acid-50100 0.036 0.075 0.45 4.5
6 0.033% Vc0.3% acid 5010 0.3 6.9 0.69 0.016 0.033
7 0.075% Vc0.3% acid 5010 0.3 7.1 0.71 0.036 0.075
8 0.033% Vc plus acid 50105 0,http://joy-bells.seesaa.net.016 0.033 3.03 30.3
9 0.075% Vc plus acid 50105 0.036 0.075 3.02 30,http://www.eigotown.com.2
10 1% Vc acid plus 0.5 1 50 105 3.17 31.7
11 5% Vc plus acid 50105 3.01 30.1 2.5 5
Experimental group representing what?
1: [Vc] no acid-free hydrochloric acid and Vc samples, although there are traces of trivalent arsenic, but very little, almost no effect on the human body.
2: [the "simulated gastric acid" no Vc] concentration of hydrochloric acid in the human stomach is 0.2% to 0.4%. Experiment with 0.3% hydrochloric acid mimic the human stomach environment,moncler outlet, without the addition of Vc, the pentavalent arsenic solution was added in the "simulated gastric acid." Pentavalent arsenic is converted to a small amount of trivalent arsenic, though not obvious reaction, but also the transformation occurs.
3: Acid [Vc] is not no more hydrochloric acid, the higher the conversion rate? Pentavalent arsenic solution was added 5% hydrochloric acid solution, this time, by the conversion of the pentavalent arsenic to trivalent arsenic in the amount of more, the conversion rate of 31.7%.
4: ["Analog orange" no acid] acid can promote the conversion of arsenic, but we want to know is whether Vc can promote the transformation of arsenic in it? Vitamin C content per 100 g Oranges 33 mg, 0.033% of Vc we simulated orange solution contained Vc, arsenic solution for detection is added, but even lower than the final conversion of the 1st experimental group.
5: ["mock orange" no acid] 100 g of a orange fruit drink vitamin C content of 75.2 mg. 0.075% Vc solution using analog orange juice Vc, arsenic solution was added, followed by detection, after the reaction, the conversion and the 4 groups the same.
No. 6: even lower under ["analog Oranges" and "simulated gastric acid"] with the addition of these two analog solutions, the conversion rate of more than just adding simulated gastric conditions.
No. 7: Under ["Analog orange juice," "simulated acid" and] the role of both analog solutions,parajumpers paris, the conversion rate is slightly increased, but minimal.
No. 8: ["analog oranges" acid] in order to verify the transformation of arsenic Vc no promotion, and will simulate Vc were added to the solution containing the acid solution and arsenic, arsenic acid than just adding a solution of low conversion rate. 9 experimental group empathy.
On the 10th, the 11th: [more] Vc acid even add more Vc, arsenic conversion rate has not changed much.
From this experiment, we can get what conclusion?
Expert FAQ
Non-toxic to toxic arsenic transformation, Vc almost no effect
Physical and chemical testing center experts, Jiangsu Province, said,http://asayake.jp/thc/epad/epad.cgi, according to the experiment, we can at least determine vitamin C for the conversion of pentavalent and trivalent arsenic arsenic, almost does not work, even with the role, but also the role of interference masking agent. The experimental results show that, contrary to the conversion of arsenic hydrochloric acid plays a significant role, the greater the acid concentration, the higher the conversion rate.
But the concentration of hydrochloric acid in the stomach of the body only 0.3%, far less than the conversion reach the desired concentration at this concentration, the conversion rate is very low.
Therefore, the network rumors, vitamin C can not eat crabs with this argument is not valid.
According to the normal food intake, there is no risk of arsenic poisoning
Some netizens said in toxicology, the median lethal dose, short LD50, describing toxic substances or radiation toxicity of commonly used indicators. The LD50 values of arsenic was 14.6mg / kg. That is, a person weighing 80 kg girls eat almost 0.6g of arsenic (14.6mg / kg × 40kg), in order to "guarantee" that she had a 50% probability of death within two weeks; even the pollution reaches the upper limit of shrimp, and All became trivalent arsenic reduction, to achieve this dose was 1200 kg eat crabs.
This statement is correct?
Experts explained that the toxicology of the median lethal dose LD50, is (such as mice, rats, etc.) for subjects for animals, not for the people, and this dose only as a reference. According to crabs containing 0.5 milligrams per kilogram of inorganic arsenic limit is calculated, even if these inorganic arsenic vitamin C can all be reduced to arsenic, in theory, only once more than 120 kilograms of edible crabs, it may happen arsenic poisoning. According to people of normal food intake, there is no risk of arsenic poisoning.
There is this one says
These grams of food? Do not believe it!
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(From the network)
