Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract

Grapefruit seed extracts are used in cosmetics, food supplements, and pesticides because of their antimicrobial properties, but suspicions about the true nature of the active compounds arose when synthetic disinfectants such as benzethonium or benzalkonium chloride were found in commercial products. The HPLC method presented herein allows the quality assessment (qualitative and quantitative) of these products for the first time. On the basis of a standard mixture of 18 preservatives most relevant for food and grapefruit products, a method was developed allowing the baseline separation of all compounds within 40 min. Optimum results were obtained with a C-8 stationary phase and a solvent system comprising aqueous trifluoroacetic acid, acetonitrile, and 2-propanol. The assay was fully validated and shown to be sensitive (LOD < or= 12.1 ng on-column), accurate (recovery rates > or = 96.1%), repeatable (sigma(rel) < or = 3.5%), precise (intra-day variation < or = 4.5%, interday variation < or = 4.1%), and rugged. Without any modifications the method could be adopted for LC-MS experiments, where the compounds of interest were directly assignable in positive ESI mode. The quantitative results of several products for ecofarming confirmed previous studies, as seven out of nine specimens were adulterated with preservatives in varying composition. The samples either contained benzethonium chloride (2.5-176.9 mg/mL) or benzalkonium chloride (138.2-236.3 mg/mL), together with smaller amounts of 4-hydroxybenzoic acid esters, benzoic acid, and salicylic acid.     

Human–wildlife conflict and attitude of local people towards conservation of wildlife in Chebera Churchura National Park,Ethiopia

Human–wildlife conflict is a serious challenge undermining the integrity of protected areas in developing countries. Developing effective human–wildlife conflict mitigation strategies requires an understanding of the conflict patterns, species involved and attitudes of local people living along protected area boundaries. We hypothesised that (1) there was a high level of human–wildlife conflict and (2) the local people would have less favourable attitudes towards problematic wild animals. We assessed patterns of human–wildlife conflict and attitudes of local people along the boundary of Chebera Churchura National Park, Ethiopia from 2012 to 2014. A total of 354 households were selected randomly for interview. A questionnaire survey, focus group discussions and direct field observations were carried out in the selected villages. The major types of human?wildlife conflict in the area include crop raiding, livestock predation, increased risk of livestock diseases and direct threats to human life. A majority of the respondents (68.1%) faced crop damage and domestic animal loss, 12.3% reported threat to humans and 0.3% reported that the wildlife might cause diseases. Close proximity of the villages to the park and seasons influenced livestock predation intensity with highest predation in the wet season (56.0%). To mitigate these problems, the local people utilised various traditional methods, including guarding. Most respondents had positive attitudes towards the conservation of wildlife. However, as the frequency of conflicts increased in the last five years, the attitudes of local people might change. Active measures are to be implemented to mitigate the problem and safeguard the future of the wildlife around the park. The park has enormous potential to benefit more local people by implementing a participatory management approach to conservation.