Sri Noegrohati

Regression models for octanol‐water partition coefficients, and for bioconcentration in fish

Octanol‐water partition coefficients (P) of a number of organochlorine insecticides (OCs) are presented. The merits of log‐log regressions between experimental ? values and calculated estimates of P, solute activity coefficients in water, solute molecular surface area data, and reversed‐phase liquid‐chromatographic net retention data, are critically evaluated for several classes of pollutants: polycyclic aromatic hydrocarbons (PAHs), chlorinated benzenes, chlorinated biphenyls and OCs. Special attention is paid to the predictive accuracy of such semi‐empirical regressions in connection with possible effects of solute molecular shape and polarity. Finally, bioconcentration and ‐accumulation of hydrophobic pollutants in fish are briefly discussed.

Impact of DDT spraying on the residue levels in soil, chicken, fish‐pond water, carp, and human milk samples from malaria infested villages in central Java

Samples were collected at some villages in Central Java, sprayed with DDT to control outbreaks of malaria, 2, 8 and 24 years before sampling. The impacts of DDT spraying on the residue levels in soil and chicken, water and fish, and human milk, and the daily intake by nursed infants are evaluated.

Regression models for some solute distribution equilibria in the terrestrial environment

Sorption coefficients (Kp) of several organochlorine insecticides (OCs) in volcanic ash silt from Central Java are presented. Selected experimental and estimated octanol‐water partition coefficient (P) values are used to study log‐log regressions with Kp data collected from the literature (PAHs, chlorophenols, phenylureas, chloro‐s‐triazines, carbamates and organophosphorus insecticides) and those of the OCs determined in the present study. Leaching distances and bioactivities in soil are correlated with the Kp values of the pesticides, and with the organic matter and the water content of the soil.

Cleanup by solid‐phase extraction and HPLC of organochlorine insecticides and PCBS in various nonfatty and fatty samples

An accurate, simple and cheap extraction and cleanup procedure for capillary GC analysis of organo‐chlorine insecticides (OCs) in vegetables (cabbage and carrots) at the ng/g level, and for soil at the μg/g level is presented. The cleanup is carried out on solid‐phase extraction (SPE) cartridges, filled with 500 mg silica, 1 g of deactivated Florisil (10% w/w water), and 100 mg of anhydrous sodium sulphate. Recoveries >90% are obtained. The cleanup of OCs in fatty samples on an HPLC LiChrosorb Si 100 column is evaluated for subsequent capillary GC analysis. Fractionation of OCs and Aroclor 1254 and 1260 on an HPLC Nucleosil 100 column appears to be satisfactory.

Sorption‐desorption kinetics of some organochlorine insecticides in silt‐water suspensions

Kinetic (batch) sorption and desorption experiments for some organochlorine insecticides in silt‐water suspensions are described. The effect of possible experimental artifacts on the results is examined. The influence of the silt/water ratio on the linear sorption coefficient and on the “nonextractable”; solute fraction is determined. The sorption process is described in terms of some kinetic models.

Degradation profile of azoxystrobin in Andisol soil: laboratory incubation

The fate of azoxystrobin in soil under the effect of different temperature is of interest because application directions specify soil-surface treatments for number of agricultural pests. Temperature is an important factor governing the rate of degradation in soil pore. The purpose of this investigation was to understand better the effect of temperature on the degradation of azoxystrobin in Japanese Andisol soil. This was done through laboratory incubation of soil at three different temperatures (5 °C, 20 °C, 35 °C). First-order kinetics could be used to describe degradation of azoxystrobin under controlled condition of temperature (r2 ˃ 94). The results showed that, during the 120-day incubation period for azoxystrobin, 64%, 70%, and 78% of applied azoxystrobin were degraded at 5 °C, 20 °C, and 35 °C, respectively. By using the Arrhenius equation, the activation energy of degradation of azoxystrobin fungicide was calculated (7.48 ± 1.74 kJ mol−1) in soils, which confirm that temperature had a significant influence on the degradation rate. Q10 value of 1.11, for azoxystrobin, indicated that the response of fungicide dissipation to temperature was large. For azoxystrobin, there was a much larger difference in dissipation rates at 5 °C and 35 °C, indicating that biological and/or chemical degradation of azoxystrobin may have nearly reached its optimum at 35 °C.

A Coarse-Grained Molecular Dynamics Simulation Using NAMD Package to Reveal Aggregation Profile of Phospholipids Self-Assembly in Water

The energy profile of self-assembly process of DLPE, DLPS, DOPE, DOPS, DLiPE, and DLiPS in water was investigated by a coarse-grained molecular dynamics simulation using NAMD package. The self-assembly process was initiated from random configurations. The simulation was carried out for 160 ns. This study presented proof that there were three major self-assembled arrangements which became visible for a certain duration when the simulation took place, that is, liposome, deformed liposome, and planar bilayer. The energy profile that shows plateau at the time of these structures emerge confirmed their stability therein. Our findings have highlighted the idea that liposomes and deformed liposomes are metastable phases which eventually will turn into planar bilayer, the stable one.

Bimodal distribution of organochlorine insecticide levels in soil due to emulsion spraying

Concentrations (c) of lindane and technical DDT have been determined in about 60 soil samples, randomly taken from a 10 × 10 m2 plot of bare soil one day after spraying. These experimental c, log c data, and literature data for dieldrin are used to examine the various residue distributions in cultivated and uncultivated soil plots. The normality of these distributions is examined with some statistical tests. All c distribution curves are more or less skew to higher c levels. From the pooled cumulative distribution curve and frequency histogram it is concluded that the found c distributions can be characterized best as bimodal. Finally, some practical recommendations are given for cost‐effective soil sampling.

ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBON IN SOME MEAT PRODUCTS

The polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds, composed two or more fused aromatic (benzene) rings, occurred in the environment due to incomplete combustion of organic matters such as forest fires, volcanic eruption, burning of fossil fuels and incorrect process of meat cooking (grilling, smoking, roasting). Healt concerns are focussed on the metabolite transformation of PAHs, which may have mutagenic, carcinogenic and terratogenic activity. Due to their hydophobicity, it is probable the compounds enter human food chain and accumulated in human lipid tissues. Therefore, environment pollution by PAHs must be considered. PAHs gain entry to human body through several routes including respiration, absorpsion through skin surface ang through food consumption that have been polluted with PAHs. In this study concentrations of PAHs (pyrene, perilene, benzo(a)anthracene, benzo(k)fluorantrene and benzo(a)pyrene) in traditional smoked meat, liquid smoked meat and roasted meat are determined. Determination of PAHs used gas chromatograph with OV 17 2% as a stationary phase, nitrogen as carrier gas and flame ionization detector. The results showed that PAHs concentrations in traditional smoked meat were higher than liquid smoked meat (41.19 ppb and 1.03 – 9.26 ppb). In the roasted meat, lipid concentration and roasting time influence PAHs concentration level. Keywords : polycyclic aromatic hydrocarbon, smoked meat, liquid smoke

CLEANING EFFECTIVITY OF SEVERAL SURFACTANS TO PESTISIDES RESIDUES ON FRESH APEL FRUITS

Intensification efforts in farming to increase productivity must consider the pesticide utilization, especially insecticide and herbicide. Several pestisides which are still used include carbofuran and organochlorine, some of them have lipofilic properties and might harm to human health. Therefore, an effort is required to washing off pesticides from farming products is one of the effort which can be performed. Since pesticides has lipofilic properties, therefore cleaning pesticides with water is not sufficient. Surfactant is required to increase washing off ability of water. Wash off ability of several surfactants circulated on the market i . e. SL, ML and A were investigated. The result showed that the wash off ability values of surfactants to DDT residues on fresh apples were 79.18 %, 75.19 % and 67.49 % for SL, A and ML respectively. The wash off effectiveness of surfactant A, SL and ML to -metrine were 85.29 %, 80.48 % and 64.47 % respectively. Key words: pesticide, cleaning efficiency surfactant, DDT, -metrine.