title: Development of an HPLC method to analyze four veterinary antibiotics in soils and aqueous media and validation through fate studies

authors: Srinivasan, Prakash

subjects: HPLC

abstract: A simple, yet robust analytical method was developed to detect and quantify three sulfonamides (SA), namely sulfamethoxazole (SMO), sulfachloropyridazine (SCP), and sulfamethazine (SM), and a macrolide tylosin (TT) in aqueous (calcium chloride and leachate solutions) and solid (agricultural soils) matrices using high performance liquid chromatography and ultra violet detection at 290 nm (TT) and 275 nm (SA) respectively. Chromatography was performed using a Phenomenex Onyx Monolithic C-18 column for TT and a C-18 Luna column for sulfonamides as single analytes eluted isocratically with a mobile phase consisting of acetonitrile: trifluoroacetic acid: tetrahydrofuran in the ratio 22.5:68:9.5 for TT, 40:55:5 for SMO, 32:63:5 for SCP and 31:64:5 for SM (v/v) at 1.0 mL min(-1) and an injection volume of 20 mu L. A gradient method to detect all three sulfonamides in a single run was also developed. The soil residue analysis consisted of extraction with dichloromethane and pre-concentration steps as the aqueous phase was measured directly. The limits of detection at an S/N (signal: noise) ratio of 3 were 20.0 mu g L-1 and 50 mu g L-1 for all sulfonamides and tylosin respectively. The average recoveries for all sulfonamides and tylosin in aqueous matrices ranged from 95 to 105% across the six concentrations investigated. Recoveries from the soils were slightly lower for sulfonamides and tylosin. The isocratic method was used to determine the sorption and degradation of sulfonamides in soils, while the gradient method was used to determine degradation kinetics and leachate concentrations in soils and aqueous systems.

text: Development of an HPLC method to analyze four veterinary antibiotics in soils and aqueous media and validation through fate studies A simple, yet robust analytical method was developed to detect and quantify three sulfonamides (SA), namely sulfamethoxazole (SMO), sulfachloropyridazine (SCP), and sulfamethazine (SM), and a macrolide tylosin (TT) in aqueous (calcium chloride and leachate solutions) and solid (agricultural soils) matrices using high performance liquid chromatography and ultra violet detection at 290 nm (TT) and 275 nm (SA) respectively. Chromatography was performed using a Phenomenex Onyx Monolithic C-18 column for TT and a C-18 Luna column for sulfonamides as single analytes eluted isocratically with a mobile phase consisting of acetonitrile: trifluoroacetic acid: tetrahydrofuran in the ratio 22.5:68:9.5 for TT, 40:55:5 for SMO, 32:63:5 for SCP and 31:64:5 for SM (v/v) at 1.0 mL min(-1) and an injection volume of 20 mu L. A gradient method to detect all three sulfonamides in a single run was also developed. The soil residue analysis consisted of extraction with dichloromethane and pre-concentration steps as the aqueous phase was measured directly. The limits of detection at an S/N (signal: noise) ratio of 3 were 20.0 mu g L-1 and 50 mu g L-1 for all sulfonamides and tylosin respectively. The average recoveries for all sulfonamides and tylosin in aqueous matrices ranged from 95 to 105% across the six concentrations investigated. Recoveries from the soils were slightly lower for sulfonamides and tylosin. The isocratic method was used to determine the sorption and degradation of sulfonamides in soils, while the gradient method was used to determine degradation kinetics and leachate concentrations in soils and aqueous systems.

year: 2012

title: Biostratigraphy, Sr isotope chronology and chronostratigraphy of the Late Eocene – earliest Miocene Te Kuiti Group, Waikato – King Country Basin, New Zealand

authors: Kamp, Peter J.J.

abstract: This report reviews and synthesises the biostratigraphy of the Te Kuiti Group based on existing sample data archived in the Fossil Record Electronic Database (FRED). Based on these faunal and floral data, New Zealand biostratigraphic stages for the Late Eocene to Early Miocene are assigned to the formations and members within the group. Analytical strontium (Sr) data and resulting numerical ages are reported here for 26 new macrofossil samples from the Te Kuiti Group, but they do not improve the accuracy of the biostratigraphy and the age information that can be derived from it. The identification of unconformity-bound sequences, the boundaries of which align with the formation contacts within the group, provide an important set of time planes within the group. The integration of the biostratigraphy and sequence stratigraphy produces a robust chronostratigraphy for the Te Kuiti Group.

text: Biostratigraphy, Sr isotope chronology and chronostratigraphy of the Late Eocene – earliest Miocene Te Kuiti Group, Waikato – King Country Basin, New Zealand This report reviews and synthesises the biostratigraphy of the Te Kuiti Group based on existing sample data archived in the Fossil Record Electronic Database (FRED). Based on these faunal and floral data, New Zealand biostratigraphic stages for the Late Eocene to Early Miocene are assigned to the formations and members within the group. Analytical strontium (Sr) data and resulting numerical ages are reported here for 26 new macrofossil samples from the Te Kuiti Group, but they do not improve the accuracy of the biostratigraphy and the age information that can be derived from it. The identification of unconformity-bound sequences, the boundaries of which align with the formation contacts within the group, provide an important set of time planes within the group. The integration of the biostratigraphy and sequence stratigraphy produces a robust chronostratigraphy for the Te Kuiti Group.

year: 2014

title: Māori, Tongan and Chinese households: Medications and elder care

authors: Nikora, Linda Waimarie

subjects: medications

abstract: Research reveals that medicines are frequently not taken as intended, stockpiled for future use, discontinued when symptoms fade or passed to others. Medications are material objects with therapeutic uses that enter into and take on meaning within people’s lives. In this way they are culturally embedded phenomena that carry meanings and shape social relationships and practices. The symbolic meanings given to medications and cultural relations are important for understanding variations in medication practices. Households with elders often contain more medications and have more complex age-related medical conditions. In households where members are engaged in the reciprocation of care among two or three generations, medications within and between these relationships take on a range of dynamic meanings. In this paper, we explore how interactions between household members affect medicines-taking practices of elders and their families from three cultural groups: Māori, Tongan and Chinese. This research was funded by the Health Research Council of New Zealand and the Marsden Fund of the Royal Society of New Zealand.

text: Māori, Tongan and Chinese households: Medications and elder care Research reveals that medicines are frequently not taken as intended, stockpiled for future use, discontinued when symptoms fade or passed to others. Medications are material objects with therapeutic uses that enter into and take on meaning within people’s lives. In this way they are culturally embedded phenomena that carry meanings and shape social relationships and practices. The symbolic meanings given to medications and cultural relations are important for understanding variations in medication practices. Households with elders often contain more medications and have more complex age-related medical conditions. In households where members are engaged in the reciprocation of care among two or three generations, medications within and between these relationships take on a range of dynamic meanings. In this paper, we explore how interactions between household members affect medicines-taking practices of elders and their families from three cultural groups: Māori, Tongan and Chinese. This research was funded by the Health Research Council of New Zealand and the Marsden Fund of the Royal Society of New Zealand.

year: 2010