| Alkaloids are physiologically active nitrogen-containing compounds, which are produced by plants.Currently, we have already known more than10,000alkaloids, according to their chemistry structure,they can be divided into4groups: quinoline alkaloids, Isoquinoline alkaloids, indole alkaloids andpyrrolizidine alkaloids. Pyrrolizidine alkaloids (PAs) are tosins exclusively biosynthesised by plants.The toxicological effects of acute exposure to PAs to livestock and humans are well known, in particular,poisonousness with1,2-unsaturated PAs is known to cause liver toxicity and have a risk of mutagenicityand carcinogenicity. Ergot alkaloids are a typical type of indole alkaloids, which are produced bymembers of the fungal family of Clacicipitaceae. If livestock intake feed or grass that contaminated bythese endophytes, they will suffer from serious acute toxicity. Symptoms associated with these acuteintoxications include vomiting, diarrhoea, cardio-vascular collapse, convulsions, agony and abortions.So, it is essential to develop a method for detection and determination alkaloids in grass. It would helpus to ensure feed safety in our country.This dissertation focus on detection and validated quantification of15alkaloids in grass byLC-MS/MS. These15alkaloids are dihydroergocristine, ergocornine, ergocristine, ergocryptine,ergocorninine, ergocristine, ergocryptinine, ergosine, atropine, retrorsine, senkirkine, seneciphylline,monocrotaline, senecionine and scopolamine. And we use the developed method to screen the grasssamples, the main contents and results are as follows:The LC-MS/MS method has been developed for the determination of15alkaloids in grass, theresults showed that: a good linear relationships were shown for15alkaloids n the range of0.004μg/L~1.0μg/L, all the correlation coefficients were greater than0.9944Their recoveries were in therange of70%-110%, and the relative standard deviation was under10%. The method detection limitswas5.0μg/kg and the method quantification limits was10.0μg/kg.We used the developed method to detect70grass samples which sent by Inner Mongolia andSichuan province and the results showed that:30samples that have alkaloids were detected, thefrequency of alkaloids detection was42.86%, the total concentration of alkaloids were10.40-106.99g/kg. And there were11alkaloids in these grass samples., the highest detection frequencyof alkaloids was ergocristinine (15.71%),the concentration was11.45-14.14g/kg. For the grasssamples which were from different cities, they showed different detection frequency of alkaloids. Thealkaloids detection frequency of grass samples from Erdos city was the lowest(15.79%). While the dataof Chifeng and Xilin Gol city were fairly high. For different kinds of grass, the alkaloids detectionfrequency of Leguminosae forage was73.33%, the concentration was11.45-14.14μg/kg。While thealkaloids detection frequency of Gramineae forages was58.33%, the concentration was10.08-26.60μg/kg。Ergocristine had the highest alkaloids detection consequency and its concentrationwas10.08-10.69μg/kg. We used the developed method to detect67native grass samples which collected in grassland inInner Mongolia and the results showed as follow:19native grass samples that have alkaloids weredetected, the frequency of alkaloids detection was28.36%, the total concentration of alkaloids were9.91-677.25μg/kg. And there were9alkaloids in these grass samples, the highest detection frequencyof alkaloids was ergocorntinine (10.45%), the concentration was5.29-11.36g/kg. For different kinds ofgrass, the highest alkaloids detection frequency of Compositae forage was monocrotaline（25.00%）, theconcentration was58.6-131g/kg. While the highest alkaloids detection frequency of Gramineae forageswas ergocorninine（45.45%）, the concentration was5.35-11.36g/kg. The alkaloids detection frequencyof15alkaloids in different parts of grass was as follow: flowe（r29.42%）＞lea（f23.88%）＞stem（18%）＞fruit（14.29%）. |
PDF Full Text Request