Eugenol diffusion coefficient and its potential to control Sitophilus zeamais in rice.

Given the insecticidal potential of eugenol as a fumigant, this work aimed to determine the diffusion coefficient of eugenol emanating from a pure standard solution (99%), as well as from clove essential oil (Eugenia caryophillata Thunb. (Myrtaceae)) through rice grain; to chemically analyse the volatile composition of commercially available eugenol and clove essential oil; and to evaluate the mortality of Sitophilus zeamais Motschulsky (Coleoptera: curculionidae) after exposure to eugenol inside a test chamber filled with rice. The solid phase microextraction method of extracting and quantifying eugenol by gas chromatography presented a good analytical response for the quantification of the analyte. There was no significant difference between the diffusion coefficient of eugenol diffusing from pure eugenol or from clove essential oil. The diffusion coefficient of eugenol through rice with the conditions herein adopted is 1.09 × 10-3 cm2 s-1. The characterization of clove essential oil confirmed the presence of eugenol as its major component (74.25%). A difference was observed in the composition of the distinct phases evaluated. The exposure of adult S. zeamais to diffused eugenol from pure eugenol over seven days resulted in significantly higher mortality rates (~37%) than eugenol diffused from clove essential oil (~11%). No differences in mortality rates were observed in individuals placed at different positions inside the test chamber during eugenol fumigation.

The occurrence of bromide in herbal drugs: is there a need for a Ph. Eur. limit?

This contribution provides an overview on the current legal requirements regarding limits for bromide and presents data on the actual bromide burden of commonly used herbal drugs. Evaluation of an extensive data base shows that results exceeding the limit of 50 mg/kg are found in specific plants which take up bromide to a high extent from the environment. Thus, positive findings of bromide in herbal drugs do not necessarily serve as a proof for methyl bromide treatment. Taking into account the ADI recommended by EMA and WHO, there are no toxicological concerns with regard to the intake of herbal teas, extracts or comminuted herbal drugs at therapeutic doses. Furthermore, the use of methyl bromide and other fumigants must be documented within the batch documentation. If stated in the batch documentation that no fumigation was carried out, it is not necessary to perform the test on bromide. In cases of a particular suspect and if toxicological concerns exist, additional testing can be performed in accordance with the limits set by Regulation (EC) No. 396/2005. For the above reasons, information obtained by performing the test on bromide is not significant for the assessment of quality. Therefore, it seems no longer necessary to maintain bromide in Ph. Eur. general chapter 2.8.13. Pesticide residues and it is recommended to delete it from Table 2.8.13.-1.

Development of a rapid resolution liquid chromatographic method combined with chemometrics for quality control of Angelicae dahuricae radix.

INTRODUCTION: Angelicae dahuricae radix (Baizhi) is a widely used traditional Chinese medicine, for which the traditional processing method has been sun-drying after harvesting. In recent years this method has been replaced by sulphur-fumigation for the sake of improving its appearance and pest control. Correct identification of sulphur-fumigated Baizhi and rapid finding of appropriate chemical markers for the quality control of Baizhi are of very great importance. OBJECTIVE: To develop a rapid and efficient method of rapid resolution liquid chromatography (RRLC) combined with chemometrics for discriminating sulphur-fumigated Baizhi and controlling its quality. METHODOLOGY: The samples were separated on a Zorbax SB-C18-column with a gradient elution programme using methanol and water. The optimal RRLC method was validated in terms of linearity, precision, stability and recovery test. In addition, hierarchical clustering analysis (HCA) and principle component analysis (PCA) were applied to differentiate the different samples. RESULTS: All the constituents were well separated within 18 min. The results of chemical fingerprinting and quantitative analysis showed that the sulphur-fumigated method obviously destroyed the phytochemical profiles of Baizhi. Moreover, the sun-dried and sulphur-fumigated Baizhi could be clearly separated by HCA and PCA, and the critical markers such as oxypeucedanin and imperatorin accountable for such differences were ultimately screened out. CONCLUSION: This study revealed that sulphur-fumigation is an inappropriate approach for processing crude drugs and should be prohibited, and that the proposed RRLC method combined with chemometrics demonstrated an efficient strategy for quality control of Baizhi.