A method in field measurement of urinary iodine.

The objective of this study is to determine a very cheap, reliable, relatively rapid portable field unit for quantitative urinary iodine measurements. As Individual Urine Excretion (IUE) approximate those of Daily Iodine Intake (DII), iodine deficiency can be measured in casual urine samples of individual. Using the criteria, the frying pot method has been introduced and modified from the long and tedious Zak’s method after Pino et al, and Robbins and Dunn et al. This modified method has many advantages. Such the assay takes 84 tubes of urine per pot in100o C paraffin oil bath and changes into water. It has been shortened from one hour to 25 minutes. Change of color to intermediate violet is observed by adding ferroine as the indicator, resulting in a standard curve reading the concentration of iodine being, in micrograms per liter. The results of 255 subjects from Mukdaharn Province indicated the reliability of the method as the results of which are the same as those using in the heating block and spectrophotometespectrophotomete. This has been confirmed by the results of 1,007 samples. This new technique provides good results; between oil and water, the results on using water are even better. This saves much money modification reduces significantly by lowering the cost of equipment. It is rapid, simple and reliable. The method is portable and valuable for measuring and monitoring iodine deficiency studies and for epidemiological studies of iodine deficiency its control in developing countries.

Rapid detection of iodine in iodised salt and iodised water essential in a program of iodine deficiency disorders control.

To determine and develop rapid on-site testing of iodine in salt and water samples and its use as field methods for monitoring and evaluation of the Iodine Deficiency Disorders (IDD) program. Methods: In order to monitor iodine in salt, the single bottle technique is recommended, utilizing SHMP (May & Baker), tapioca flour, KI and sodium azide. Secondly, to monitor iodine in water, the double bottle technique is employed and this utilizes 3N HCl as a substitute for SHMP to acidify flour, KI and sodium azide. Results: In salt, it is not positive until the colour starts to change from brown to black. In water, when it is positive reaching beyond an optimum level at 100-200 mg of iodine per litre, the colour starts to appear as faint blue and becomes darker blue as concentration of iodine increased. Discussion: Statistically, Spearman rank correlation co-efficient and the prediction method showed approximation of the two methods in estimation of iodine levels, indicating the interchangeability of the eyesight and it can be used in screening in place of the spectrophotometer. Conclusion: These techniques are cheap, simple and effective. This allows the monitoring kit to be beneficial and easy to use. These methods are ordinary and natural, and thus, in harmory with Thai culture and customs.

Urine iodine inresligalion in Thailand.

The heating block method is a method for the routine determination of urine iodine that has been modified from the Program Against Micronutrient Malnutrition (PAMM) method. Normal values of adult urine iodine (age 35-70 years) in Bangkok were (mean + SD) 110.9+ 74.6 with a median values of 96.8 ตg/L (n = 66). Urine iodine values of adults from Maehongson and Petchabun were (mean + SD) 465.1+ 293.1 with a median value of 399.5 ตg/L (n=86), and 127.8+ 74.1 with a median value of 115.4 mg/L (n = 140), respectively. The mean and SD of the iodine content of urine from school children (age 7-12 years) in Uttraradit, Maehongson and Trang were 401.0+ 373.2 (n = 77), 1,171.1+ 1,078.4 (n = 97) and 275.0+ 399.4 (n = 46), and the median values were 264.5, 998.6 and 137.0 mg/L, respectively. There was no change in urine iodine concentration over three years despite storage a 37oC, 4 oC and 0 oC. We have participated in the PAMM-Centers for Disease Control and Prevention (CDC) Inter-Laboratory Urine Iodine Quality Assurance Program to fulfill quality assurance criteria in our testing. The results of three blind urine iodine levels were well correlated to consensus mean and %CV for inter assays were less than 15.

An investigation into methods of urine iodine analysis for use among villagers with goitre.

A modified Zak’s method has been used in this laboratory, but was subjected to contamination and produced occasional inconsistent results. Two simple ways for the determination of iodine in urine are herein described. The better one is by modified PAMM method. Briefly, destruction of organic matter in urine by acid digestion is carried out prior to determination by the Sandell and Kolthoff reaction. The Coefficient of Variation (CV) is below 10%. Iodine contents as low as 6.5 ug/L, can be detected. The proposed acid digestion procedure offers some advantages over the traditional acid digestion : e.g. low iodine losses, not complicated, and less harsh digestion. The method does not require large samples (250 ul or below) and one technician can easily handle 100 samples per day. The results obtained by this method are well correlated between the simple methods and agree with those recorded by other workers. This is also in agreement with Zak’s method (Intraclass Correlation Coefficient of 0.55). The proposed method is rapid, simple, cheap and suitable for the research investigations on iodine deficiency goitre in areas where it is endemic.

Optimized nuclear techniques and thyroid function studies in the newborn in iodine-deficient areas of Thailand.

Cord blood samples, as sera (n=4,753) and dried blood spots (n=855) obtained from subjects in iodinedeficient districts in northern Thailand, were studied for T4 and TSH. The methodology was optimized by the used of NETRIA bilk reagents and in-house methods were developed to adapt them for cost reduction, convenience and precision/accuracy. The biochemical findings with cut-off values at < 3 µg/dl for T4 and >50 mIU/L for TSH as confirmed by <1ng/dl for FT47 showed 16 cases (0.34%) of neonatal chemical hypothyroidism (NCH) varying from 0.18 to 1.59 percent of 4,753 cases. Out of the total 4,753 cases, 1.45 percent (n=96) could benefit from thyroxine administration. In this research project, the screening indicated a mild to moderate degree of IDD severity. The findings are useful for epidemiological monitoring and for advocacy of the IDD prevention and control programme.

Iodine deficiency disorders: Recent experience with iodine technology in Thailand.

For the control Iodine Deficiency Disorders (IDD) in Thailand, simple methods for iodination of various food supplements have been introduced by making use of: a) a single bottle of concentrated KIO3 solution which can be prepared by village health volunteers. Iodine may be administered by consumers by dripping the concentrate into drinking water containers belonging to village households, water for school lunch programmes, by spray mixing with salt or by dripping into fish sauce. b) twin bottle for instant detection of iodine in salt and water. This instant test is very useful for on site monitoring and hence surveillance. On a mass scale, iodination of common salt was undertaken by a simple but high capacity spraying machine or by manual mixing on a spraying table. At village level, salt iodination can be undertaken by hand spraying in a plastic basin. Iodination of drinking water can be facilitated either by using a single dropper bottle of conc KIO3 solution, or iodinators. On a limited scale, oral lipiodol has been utilized with success and the synthesis of iodized oil has been attempted. Supporting evidence from field trials confirmed the effectiveness of present methods of control via the iodated salt programme, (1962-1968), iodinated water in village households and school lunch programmes (1986-1988), iodinated water by iodinators (1981-1988), oral iodized oil (1987-1989), and iodinated water and iodated salt (1988-1989). Education transfer, and pitfalls found in the control and evaluation programmes were carefully followed up. Future projections of the control programme have been discussed.