Antibacterial Activity of The Gamal Leaf (Gliricidia sepium) Ethanol Extract on the Growth of Streptococcus mutans. Streptococcus mutans is a positive gram bacteria which cause dental caries. From the several previous studies, Gamal leaf has been predicted as the antibacterial agent because of their active substance such as tannins, alkaloids, saponins, and flavonoids. The objective of the study was to know the antibacterial activity of ethanol extract of Gamal leaf (Gliricidia sepium) for Streptococcus mutans in various concentrations. This study was a true experimental with post-test only control design. The determination of antibacterial activity in this study was conducted by using Kirby Bauer disk diffusion method with the various concentrations, there were 40, 50, 60, 70 and 80%. The positive and negative controls in this study were 30 µg disk diffusion of chloramphenicol and the 96% of ethanol. The average inhibition of zone diameter in the concentrations of 40, 50, 60, 70 and 80% were 11.3, 12.3, 13.4, 15.3 and 19.2 mm, respectively. One Way ANOVA statistical analysis showed that the value of p was 0.000, it can be concluded that the ethanol extract of Gamal leaf (Gliricidia sepium) have strong antibacterial activity, especially to Streptococcus mutans bacteria. Abstrak: Aktivitas Antibakteri Ekstrak Etanol Daun Gamal (Gliricidia sepium) pada Berbagai Konsentrasi terhadap Pertumbuhan Bakteri Streptococcus mutans secara In-Vitro.Streptococcus mutans merupakan bakteri gram positif penyebab utama terjadinya karies gigi. Berdasarkan beberapa hasil riset terdahulu, daun gamal diperkirakan memiliki aktivitas antibakteri yang cukup baik karena kandungan beberapa senyawa metabolit sekundernya seperti tanin, alkaloid, saponin, dan flavonoid. Penelitian ini bertujuan mengetahui aktivitas antibakteri ekstrak Etanol daun gamal (Gliricidia sepium) pada berbagai konsentrasi terhadap pertumbuhan bakteri Streptococcus mutans secara in-vitro. Metode penelitian true experimental dengan desain penelitian post-test only control design. Penentuan aktivitas anti bakteri dilakukan dengan menggunakan metode difusi cakram Kirby Bauer dengan lima konsentrasi uji yaitu konsentrasi 40, 50, 60, 70 dan 80%. Kontrol positif berupa cakram disk antibiotik Kloramfenikol 30µg dan kontrol negatif yaitu Etanol 96%. Berdasarkan hasil penelitian, diketahui bahwa rata-rata diameter zona hambat pada konsentrasi 40, 50, 60, 70 dan 80% berturut-turut adalah sebesar 11,3; 12,3; 13,4; 15,3 dan 19,2 mm. Uji statistik One Way Anova dengan nilai p 0,000 disimpulkan bahwa ekstrak etanol daun gamal (Gliricidia sepium) memiliki aktivitas antibakteri yang kuat, terutama terhadap bakteri Streptococcus mutans.

Nitrite is one of important food additive that used as a preservative and curing agent for the meat product. Since the adverse effect of nitrites to the human health has been reported, the government regulated maximum allowable nitrite content in meat product is 125 mg/kg. Hence, continuous monitoring of the existence of nitrite, especially in the meat products are important to conducted. Quantitative analysis of nitrite in the meat product, especially sausage has been described. The spectrophotometric measurement of the nitrite contents was conducted by using Griess method. The absorbance of both standard solution and sample carried after 30 minutes at the maximum wavelength 520 nm. A linier calibration curve was obtained in the range of 0.1-0.5 ppm, with the R2 value is 0.997. Subsequently, the method was applied to determine the nitrit contents in sausage samples. The spectrophotometric determination showed there were 6 samples have nitrite contents more than maximum allowable nitrite content in the meat product.

A simple spectrophotometric method was used to determine the phosphate content in the water sampels. The method is based on the formation of molybdenum blue complex from the reaction of orthophosphate and ammonium molybdate followed by reduction with ascorbic acid in the aqueous sulfuric acid medium. The color intensity of the molybdenum blue complex is proportionally to the phosphate content in the solution. The system obeys Lamber-Beer’s Law at the 890 nm in the concentration range of 0.1-1 mg P/L and the linier calibration graph was obtained with the slope, 0.6334, intercept, 0.0074 and correlation coefficient of 0.9988. This official method was also used for the quantitative analysis of phosphate in the water samples and the satisfactory result was obtained. The range of phosphate concentration in the water samples are 0.033 – 2.943 mg P/L.

A simple spectrophotometric method was used to determine the phosphate content in the water sampels. The method is based on the formation of molybdenum blue complex from the reaction of orthophosphate and ammonium molybdate followed by reduction with ascorbic acid in the aqueous sulfuric acid medium. The color intensity of the molybdenum blue complex is proportionally to the phosphate content in the solution. The system obeys Lamber-Beer’s Law at the 890 nm in the concentration range of 0.1-1 mg P/L and the linier calibration graph was obtained with the slope, 0.6334, intercept, 0.0074 and correlation coefficient of 0.9988. This official method was also used for the quantitative analysis of phosphate in the water samples and the satisfactory result was obtained. The range of phosphate concentration in the water samples are 0.033 – 2.943 mg P/L.

Final Waste Disposal Area at Suwung, Denpasar is one of the final waste disposal area that uses an open dumping system for the waste management techniques. These waste management techniques cause the lack of the groundwater quality. On the other hand, this groundwater is still being used as a main water source by the residents around the final waste disposal area. The aim of the study was to determine of the lead concentration in the well water at the Suwung Waste Disposal Area. This research uses descriptive method with observational approach while the analysis of lead was conducted by using atomic absorption spectrophotometry (AAS). Based on the results, it is proved that there is 1 sample contains of the lead concentration more than maximum allowable of lead according to the Minister of Health of Indonesia No. 416/MENKES/PER/IX/1990. The excess of lead concentration in the water samples may influenced by the distance of the dug wells from waste disposal area which does not meet the requirements, so the pollution occur easily.Keywords: Final waste disposal area, lead determination, atomic absorption spectrophotometry (AAS)