APPLICATION OF QuEChERS METHOD FOR MULTI-RESIDUE PESTICIDES DETERMINATION IN LETTUCE AND APPLE USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY

This study investigated the use of the QuEChERS method for the analysis of 13 pesticides on apples and lettuces. Comparison between two methods: Citrate- (buffered and unbuffered) and acetate (buffered and unbuffered). A range of pesticides –pirimicarb, diazinon, chlorpyrifos, azoxystrobin, pendimethalin, cyprodinil, boscalid, chlorothalonil, fenhexamid were selected for this study. Triphenyl phosphate was used as the internal standard. Results obtained revealed very high percentage recoveries for the majority of the pesticides screened for with recoveries of 66.3 to 109.8% for the citrate buffered, 72.5 – 120.8% for citrate unbuffered, 53.8 – 102% for acetate buffered and 54 – 105.3% for acetate unbuffered experiments carried out using apple samples. % recoveries obtained for the lettuce samples were 32.2 to 120.5% for the citrate buffered, 33.7 – 115.0% for citrate unbuffered, 53.8 – 107.4% for acetate buffered and 54 – 105.3% for acetate unbuffered experiments. % recoveries obtained for the apple samples were 64.3 – 109.8% for the citrate buffered, 72.5 – 120.8% for the citrate unbuffered, 60.3 – 102.0% for the acetate buffered and 54 – 120.5% for acetate unbuffered. Pendimethalin and cyprodinil gave the poorest recoveries while chlorothalonil gave the best recoveries for both the different methods and samples. The organophosphorus pesticides (diazinon and chlorpyrifos) gave relatively good recoveries especially for the apple samples. Comparison of sample recoveries revealed a more favourable recovery for the apple samples compared to the lettuce samples. The limit of detection was also determined to be ~0.02µg/L (6µg/kg). http://dx.doi.org/10.4314/njt.v35i3.1

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change : UNEP Environmental Effects Assessment Panel, Update 2020

This assessment by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) provides the latest scientific update since our most recent comprehensive assessment (Photochemical and Photobiological Sciences, 2019, 18, 595-828). The interactive effects between the stratospheric ozone layer, solar ultraviolet (UV) radiation, and climate change are presented within the framework of the Montreal Protocol and the United Nations Sustainable Development Goals. We address how these global environmental changes affect the atmosphere and air quality; human health; terrestrial and aquatic ecosystems; biogeochemical cycles; and materials used in outdoor construction, solar energy technologies, and fabrics. In many cases, there is a growing influence from changes in seasonality and extreme events due to climate change. Additionally, we assess the transmission and environmental effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, in the context of linkages with solar UV radiation and the Montreal Protocol.Peer reviewe

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change : UNEP Environmental Effects Assessment Panel, Update 2021

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.Peer reviewe