title: Development of an Ion Chromatography Method for the Analysis of Nitric Acid Oxidation Reactions of Common Sugars

authors: Davey, Cara-Lee

subjects: nitric acid oxidation

abstract: The large scale nitric acid oxidation of common sugars into their corresponding aldaric acids is being investigated as an important source of potentially useful components for industrial applications such as polymers. 

This thesis details the development of an Ion Chromatography (IC) method for the analysis of these oxidation mixtures and related samples from the work-up and purification processes. The method was developed for use with a Dionex ICS2000 IC system equipped with an AS11-HC column and utilising suppressed conductivity detection. IC proved to be a useful, versatile and straightforward method of studying the reactions and their products. 

The detected ions include but are not restricted to the anionic salt forms of: D-Glucaric acid, Xylaric acid, Mannaric acid,  D-gluconic acid and both keto forms of the same, D-xylonic acid, D-mannonic acid, glycolic acid, oxalic acid, tartaric acid and tartronic acid. Nitrate from the nitric acid used in the oxidation is often observed.  The results compare favorably to GC-MS and HPLC analysis of similar samples. An overview of the theory and operation of the instrument along with the method development and results from application to the oxidation mixtures and related samples are presented. 

As part of the investigation into the range of utility of IC for studying these reactions, a study was made of the retention behaviour of a large number of simple and low molecular weight (LMW) carboxylic acids eluted by the ion chromatography system in use. The results of this study are included with an explanation of the major factors affecting anion retention on the column

text: Development of an Ion Chromatography Method for the Analysis of Nitric Acid Oxidation Reactions of Common Sugars The large scale nitric acid oxidation of common sugars into their corresponding aldaric acids is being investigated as an important source of potentially useful components for industrial applications such as polymers. 

This thesis details the development of an Ion Chromatography (IC) method for the analysis of these oxidation mixtures and related samples from the work-up and purification processes. The method was developed for use with a Dionex ICS2000 IC system equipped with an AS11-HC column and utilising suppressed conductivity detection. IC proved to be a useful, versatile and straightforward method of studying the reactions and their products. 

The detected ions include but are not restricted to the anionic salt forms of: D-Glucaric acid, Xylaric acid, Mannaric acid,  D-gluconic acid and both keto forms of the same, D-xylonic acid, D-mannonic acid, glycolic acid, oxalic acid, tartaric acid and tartronic acid. Nitrate from the nitric acid used in the oxidation is often observed.  The results compare favorably to GC-MS and HPLC analysis of similar samples. An overview of the theory and operation of the instrument along with the method development and results from application to the oxidation mixtures and related samples are presented. 

As part of the investigation into the range of utility of IC for studying these reactions, a study was made of the retention behaviour of a large number of simple and low molecular weight (LMW) carboxylic acids eluted by the ion chromatography system in use. The results of this study are included with an explanation of the major factors affecting anion retention on the column

year: 2008

title: Use of three New Zealand chironomids, Chironomus zealandicus, Chironomus sp. a and Polypedilum pavidus (lnsecta: Diptera) as biotoxicity test organisms

authors: Kanapathippillai, Jeyasingham

abstract: Three species of New Zealand chironomid, Chironomus sp. a, Chironomus zealandicus and Polypedilum pavidus were studied for their potential as biological indicators of freshwater environmental pollution and for use as laboratory bioassay species. 

A standard methodology was developed to successfully culture these three chironomids in the laboratory in order to obtain all larval stages of each species for laboratory bioassays.
 
Head capsule deformities and physical wear were examined for C. zealandicus collected from four study sites in summer and winter from 1994 to 1996, and from larvae reared for two successive generations in a control substrate. Results showed that the incidence of head capsule deformity was influenced by both substrate type and season. The cause of this deformation was not identified although sediment chemistry, genetics and other physico-chemical factors are collectively implicated. Significantly greater frequency of physical wear of head capsule structures in larvae collected from Hamurana Stream and a progressive decline of wear in larvae reared on a paper towel control substrate indicated that feeding activity on a relatively coarse substrate may have caused the wear. 

A field survey indicated that, although all these species were present at every site, they show particular site preference. A life cycle test was performed to investigate the substrate preference of C. sp. a and C. zealandicus on sediments collected from the four study sites, Hamilton Lake, Lake Ngaroto and Hamurana Stream and Sulphur Point of Lake Rotorua. Results showed that Lake Ngaroto sediment and Sulphur Point sediment favour C. sp. a and C. zealandicus respectively.

The acute toxicity of arsenite (Aѕ³⁺), arsenate (Aѕ⁵⁺) and copper (Cu²⁺) under different conditions was investigated. Although C. zealandicus and C. sp. a are closely related, they showed considerable difference in sensitivity to arsenic and copper. A number of biological (age), chemical (valency state), and physical (season, temperature) factors were observed to affect the toxicity of arsenic and copper to the test chironomid species. Chronic sublethal effects of arsenic-spiked sediments from Hamilton Lake and Lake Ngaroto and a paper towel substrate on C. zealandicus and C. sp. a were also studied under laboratory conditions. This study showed that the sensitivity of the chironomid species varied depending on the length of exposure to the spiked sediment, the number of endpoints examined, and other laboratory testing conditions such as renewal of dilution water. This experiment also indicated that C. zealandicus was more resistant to arsenic spiked sediment than C. sp. a. A protocol was developed for conducting standard sediment toxicity tests. 

The results of this work imply that although one or more of the chironomid species used in this study may be used as a bioindicator in monitoring freshwater lakes, use of these species as indicator organisms should be carefully assessed based on their occurrence in the location concerned. Although these three species may be used in laboratory bioassays, C. zealandicus appeared to be more convenient because of its continuous abundance at study sites and tolerance to physical handling.

text: Use of three New Zealand chironomids, Chironomus zealandicus, Chironomus sp. a and Polypedilum pavidus (lnsecta: Diptera) as biotoxicity test organisms Three species of New Zealand chironomid, Chironomus sp. a, Chironomus zealandicus and Polypedilum pavidus were studied for their potential as biological indicators of freshwater environmental pollution and for use as laboratory bioassay species. 

A standard methodology was developed to successfully culture these three chironomids in the laboratory in order to obtain all larval stages of each species for laboratory bioassays.
 
Head capsule deformities and physical wear were examined for C. zealandicus collected from four study sites in summer and winter from 1994 to 1996, and from larvae reared for two successive generations in a control substrate. Results showed that the incidence of head capsule deformity was influenced by both substrate type and season. The cause of this deformation was not identified although sediment chemistry, genetics and other physico-chemical factors are collectively implicated. Significantly greater frequency of physical wear of head capsule structures in larvae collected from Hamurana Stream and a progressive decline of wear in larvae reared on a paper towel control substrate indicated that feeding activity on a relatively coarse substrate may have caused the wear. 

A field survey indicated that, although all these species were present at every site, they show particular site preference. A life cycle test was performed to investigate the substrate preference of C. sp. a and C. zealandicus on sediments collected from the four study sites, Hamilton Lake, Lake Ngaroto and Hamurana Stream and Sulphur Point of Lake Rotorua. Results showed that Lake Ngaroto sediment and Sulphur Point sediment favour C. sp. a and C. zealandicus respectively.

The acute toxicity of arsenite (Aѕ³⁺), arsenate (Aѕ⁵⁺) and copper (Cu²⁺) under different conditions was investigated. Although C. zealandicus and C. sp. a are closely related, they showed considerable difference in sensitivity to arsenic and copper. A number of biological (age), chemical (valency state), and physical (season, temperature) factors were observed to affect the toxicity of arsenic and copper to the test chironomid species. Chronic sublethal effects of arsenic-spiked sediments from Hamilton Lake and Lake Ngaroto and a paper towel substrate on C. zealandicus and C. sp. a were also studied under laboratory conditions. This study showed that the sensitivity of the chironomid species varied depending on the length of exposure to the spiked sediment, the number of endpoints examined, and other laboratory testing conditions such as renewal of dilution water. This experiment also indicated that C. zealandicus was more resistant to arsenic spiked sediment than C. sp. a. A protocol was developed for conducting standard sediment toxicity tests. 

The results of this work imply that although one or more of the chironomid species used in this study may be used as a bioindicator in monitoring freshwater lakes, use of these species as indicator organisms should be carefully assessed based on their occurrence in the location concerned. Although these three species may be used in laboratory bioassays, C. zealandicus appeared to be more convenient because of its continuous abundance at study sites and tolerance to physical handling.

year: 1999

title: Reo Rua Pukapuka Pikitia: Whānau drawing on their community cultural wealth to create strategies for developing Te Reo Rangatira

authors: Brouwer, Jacqui

abstract: The use of Te Reo Māori in Early Childhood Education in Aotearoa New Zealand is mandated in the ECE curriculum. Research shows that picturebooks are powerful tools in language learning, but there is a lack of research concerning the use of bilingual picturebooks by whānau to support Māori language learning in a New Zealand kindergarten. This research presents findings from a 4-week programme in which five whānau members were introduced to several types of dual language picturebooks (Reo Rua Pukapuka Pikitia, RRPP) in a Puna Pukapuka Pikitia (PPP). Whānau explored RRPP and suggested how they could bring Reo Rangatira from RRPP into their homes to support language learning. Their suggestions aligned with Ellis’s principles of effective language teaching (Ellis, 2010) including the development of formulaic phrases, following the ways in which tamariki naturally learn language, encouraging opportunities for tamariki to speak and listen, as well as having interactions linked to RRPP.

text: Reo Rua Pukapuka Pikitia: Whānau drawing on their community cultural wealth to create strategies for developing Te Reo Rangatira The use of Te Reo Māori in Early Childhood Education in Aotearoa New Zealand is mandated in the ECE curriculum. Research shows that picturebooks are powerful tools in language learning, but there is a lack of research concerning the use of bilingual picturebooks by whānau to support Māori language learning in a New Zealand kindergarten. This research presents findings from a 4-week programme in which five whānau members were introduced to several types of dual language picturebooks (Reo Rua Pukapuka Pikitia, RRPP) in a Puna Pukapuka Pikitia (PPP). Whānau explored RRPP and suggested how they could bring Reo Rangatira from RRPP into their homes to support language learning. Their suggestions aligned with Ellis’s principles of effective language teaching (Ellis, 2010) including the development of formulaic phrases, following the ways in which tamariki naturally learn language, encouraging opportunities for tamariki to speak and listen, as well as having interactions linked to RRPP.

year: 2023