Praktikum Geokimia: Teknik Penanganan Sampel Air

Summary

This script outlines the essential steps for geochemical water sampling, including selecting a sampling location, collecting, filtering, and preserving the sample. It details the necessary equipment and materials, such as pH paper, beakers, and various bottles, along with safety gear and a hannameter for measurements. The process involves rinsing equipment, observing physical and chemical properties, and recording data like pH, EC, and TDS. Special preservation methods are highlighted for different analyses, emphasizing the importance of safety and accurate data collection for geochemical studies.

Takeaways

• 📍 Geochemical water sampling involves three main steps: choosing the location, collecting the sample, and filtering and preserving it.
• 🧰 Preparation of equipment and materials is essential before field observation and sample collection.
• 🔬 Necessary equipment includes universal pH paper, beaker glass, glass bottles, isotope bottles, HDPE bottles, filters, syringes, and a water dipper.
• 🧴 Materials needed for the process are Aquadest, Zn acetate 2 M, and nitric or hydrochloric acid.
• 🌡 The hannameter instrument is used for measuring pH, temperature, electrical conductivity (EC), and total dissolved solids (TDS).
• 📊 The physical properties of water, such as color, odor, and EC, are observed directly, while pH and TDS are measured using the hannameter.
• 💧 Water sampling should be conducted carefully to avoid contamination, preferably in flowing water to prevent sediment collection.
• 🌡️ Temperature is an important physical property to note during the sampling process, as it can affect water quality.
• 🚰 All equipment must be rinsed with the water sample at least three times to ensure no contaminants alter the analysis.
• 🔒 Proper preservation methods are crucial for different types of analysis, such as adding strong acid for cation analysis or Zn acetate for sulfide analysis.
• 🏥 The samples must be transported to the laboratory quickly in a cooler box to maintain their integrity for analysis.

Q & A

What are the general steps involved in collecting a water sample for geochemical analysis?

The general steps involved in collecting a water sample for geochemical analysis are choosing the sampling location, collecting the water sample, and filtering and preserving the water sample.

What is the first preparatory action required before conducting field observation and sample collection?

The first preparatory action is to prepare the necessary equipment and materials for water sampling.

List the equipment needed to collect a water sample as mentioned in the script.

The equipment needed includes universal pH paper, beaker glass, glass bottle with a rubber seal, isotope bottle, HDPE bottle, filter, syringe, and water dipper.

What materials are required along with the equipment for water sampling?

The materials required are Aquadest, Zn acetate 2 M, nitric acid or hydrochloric acid.

What are the supporting equipment and materials mentioned for safety and measurement purposes?

Supporting equipment and materials include latex gloves, a mask, and a hannameter instrument.

Can you describe the specific sampling location mentioned in the script?

The sampling location is at coordinate 49M 430567 E 914162 S with an elevation of 117 meters above sea level, located in Code River, Sendowo, Sinduadi Village, Mlati District, Sleman Regency, Daerah Istimewa Yogyakarta, 500 meters to the southwest of the Geological Engineering Department, Gadjah Mada University.

When was the water sampling conducted, and what was the weather condition on that day?

The water sampling was conducted on Thursday, 22 October 2020, with the weather being partly cloudy and a temperature of 28 degrees Celsius.

How should the water dipper be prepared before collecting the water sample?

The water dipper should be rinsed using the water sample for three times to ensure no contaminants are present that could alter the analysis results.

What are the physical and chemical properties that need to be observed and measured during water sampling?

The physical properties include temperature, color, odor, and electrical conductivity (EC). The chemical properties include pH and total dissolved solids (TDS).

How is the pH, electrical conductivity, and TDS measured using the hannameter instrument?

The hannameter instrument is arranged, ensuring the sensor cap does not dry out. The sensor is inserted into the water sample, and the readings for pH, EC, and TDS are recorded.

What preservation methods are used for different types of water sample analysis?

For anion analysis, no preservation is needed. For cation analysis, a strong acid is added until the pH is less than 2. For sulfide analysis, 1 drop of Zn acetate 2 M is added for every 25 ml of sample.

How should the filtered water sample be stored before being brought to the laboratory?

The filtered water sample should be put into isotope bottles and HDPE bottles, and then placed into a cooler box to maintain its condition before being transported to the laboratory.

What is the purpose of preserving a backup sample in a glass bottle with a rubber seal?

The backup sample in a glass bottle sealed with a rubber seal is kept for future reference or in case the primary samples are compromised or additional tests are needed.