HPLC and spectrophotometry methods for measuring melamine migration from melamine dishes to food simulants.

Melamine is an organic-based chemical usually found as enriched white nitrogen crystals. Since melamine is used for manufacturing food dishes and containers, there are concerns about melamine migration from the dishes into foods and subsequently the human body, particularly in children. As there are no routine techniques to measure melamine migration in food quality control laboratories in Iran, we here aimed to validate HPLC and spectrophotometry methods to measure migration of this substance. The HPLC and spectrophotometry techniques were adopted and validated. The level of melamine migration was measured in melamine ware of five brands in Iran market. Distilled water and acetic acid 3% were used as simulants. The dishes were in contact with the simulants for 90 min at 90 °C.The accuracy and precision were obtained as 94.9 and 95.3% for HPLC and 95.3% and 96.2% for spectrophotometry, respectively. Furthermore, the limit of detection (LOD) and limit of quantification (LOQ) were obtained as 145 and 435 ng/ml for HPLC, and 200 and 605 ng/ml for spectrophotometry, respectively. Our results indicated that HPLC can be a reliable method to measure low-level melamine. The spectrophotometry could also be applied as a feasible, accurate, and cost-effective method for measuring melamine in foodstuffs.•This research has tried to adopt a method to measure melamine migration in the regions where there are no routine techniques to measure melamine migration the same as Iranian food laboratories.•The validation results of HPLC and spectrophotometry methods showed 94.9% accuracy and 95.3% precision and 95.3 and 96.2% for spectrophotometry respectively which were reliable.•HPLC can be a reliable method to measure low-level melamine. The spectrophotometry could also be applied as a feasible, accurate, and cost-effective method for measuring melamine in foodstuffs.

Melamine migration measurement through spectrophotometry device and the effect of time and tableware type on it.

Melamine is an organic-based chemical material widely used in the production of tableware. Given the adverse effects of melamine on human health, melamine tableware can be a source for its introduction into the human body. The aim of this study was to use a simple method for monitoring the rate of melamine migration from the tableware to food and the effect of time and tableware on this migration. To measure the migration, spectrophotometry was used. The limit of detection (LOD) of the method was 0.2 (µg/ml), which is functional for measuring the rate of migration. The investigation of sample migration of melamine tableware revealed that migration has occurred across all samples. The rate of migration in all samples was less than the standard level of the European Union (30 µg/ml). Statistical analysis indicated that time is an important factor in melamine migration, which significantly increased (p<0.05) in 93% of cases with lengthening the contact time from 30 minutes to 90 minutes. The type of tableware (new or old) and production conditions (standard or non-standard) were found to significantly affect (p<0.001) the rate of migration. Statistical analysis of the results suggested that old tableware increased melamine migration in 41% of cases (p<0.05). Non-standard tableware significantly (p<0.001) increased the rate of migration and thus the effect of non-standard production on melamine tableware was more significant than the age of the tableware.

Data on the levels of Melamine- migration from Melamine- ware products and effect of food type and time on it.

Nowadays, Melamine- containers is widely use to because of heat- resistant. Due to the effects of Melamine- on human health, constant and long-term usage of Melamine- containers can be a source of Melamine- exposure to human body. The objective of this research was to measure the levels of Melamine- migration from Melamine- ware-products into foods at different test conditions and Effect of food type and Time on it. Spectrophotometer UV/VIS method was used to detect the limits of Melamine- and the method was based on the in the complex of Melamine- formaldehyde and Uranin (a ketone group).The limit of detection (LOD) of the method was 0.2 (µg/ml) which is functional for measuring. Migration was less than the standard level of European Union (30 µg/ml). In this study, 3% acetic acid, distilled water and 15% ethanol were used as simulants. The results showed the temperature is an important factor in Melamine- migration and in 97% of cases, with increasing temperature from 30 to 90 there is a significant increase (P < 0.05) in Melamine- migration furthermore migration from acidic simulants was more than alcoholic and neutral ones (p < 0.001).

Data about knowledge and tendency towards organic foods use in Tehran.

Improper use of chemical fertilizer and pesticide poses not only threats to the environmental safety but also major public health issues globally. The adverse effects of chemical fertilizers and pesticides forced agricultural scientist to look for safer methods such as organic farming. This study was aimed at assessing the knowledge and tendency towards organic foods use among people of living in a megacity, Tehran. Data was collected from "fall exhibition" and "health food exhibition" participants using pretested questionnaire. Data were entered, cleaned and analyzed by SPSS version 17. T-test, ANOVA and Regression analysis were carried out and the association was considered significant at p-value less than 0.05. A total of 400 respondents participated in the study, making a response rate of 100%. There were reverse relation between knowledge and accessibility and positive relation between trust, marriage and gender and no relation with price. Building trust in consumer, and allocation of a special label, known logos and ways to track most of the products sold as organic foods seems necessary for increasing consumption.

Measurement of melamine migration from melamine-ware products by designed HPLC method and the effect of food-type on the level of migration.

Melamine-ware is widely used around the world. There is a public health concern as regards the safety of melamine when exposed to food. This study was carried out to measure the level of melamine migration in melamine-ware products by HPLC method and the effect of food-type on the level of melamine migration. In food control laboratories in Iran, there is no common method to measure and monitor melamine migration, hence a method using HPLC technique was adopted and validated to solve this problem. The validation results showed the reliability with 94.9% accuracy and 95.3% precision. Furthermore, the limit of detection (LOD) and quantification (LOQ) were 0.145 and 0.435 µg/ml, which for a new method were within acceptable ranges. Melamine migrations from 4 most available melamine wares were measured. Distilled water, 3% acetic acid and 15% ethanol were used as food simulant at 30 °C for 90 min. Although melamine migration occurred in all samples and acidic conditions had a significant effect, the values were not higher than the European standard (30 µg/ml). The study revealed that the HPLC method was valid and could be applied and developed to measure melamine migration. However, precautions should be considered while choosing melamine-ware utensil as long-term exposure to this substance has a negative effect on health, especially on the kidneys.