H2S Water Testing Kit

Introduction :-

The H₂S water testing kit is a simple method to detect the presence of harmful bacteria in drinking water. It identifies bacterial contamination by detecting hydrogen sulfide (H₂S) gas produced by certain bacteria, indicated by a color change—usually turning black in contaminated samples.

Materials :-

Forecep

Petri plate

Filter paper

Beaker

Plastic bottle

Preparation of media for 200 H2S kit strip :-

Chemicals	Quantity
Bacteriological grade peptone	80gm
Dipotassium hydrogen phosphate	6.0gm
Ferric ammonium nitrate	3.0gm
Sodium thiosulphate	4.0gm
L – cysteine HCl	0.5gm
Liquid soap	4.0ml
Distilled water	200ml

• Measure 200 ml of distilled water into a glass beaker, then add and dissolve the chemical.

• Stir until powder media is completely soluble in water.

• Cut the filter paper into pieces of 8 × 2.5 cm to make 200 strips.

Check pH :- pH should be maintained between 6.5 to 7.2.

Sterilization process :-

1. Clean the glasswares such as forecep, petri plate etc.
2. Autoclave the media, forecep, filter paper at 121°C for 15-20 minutes.
3. After autoclaving, remove the media, filter paper and glasswares from sterilizer and place them in laminar air flow.
4. Take 30 ml new 200 plastic bottles.
5. Open the caps of bottle and keep in hot air oven at 55-60°C for 20 minutes.
6. Sterile the bottles using Laminar Air Flow for 1 hrs.It helps to prevent Bacterial contamination.

Methodology :-

1. Dip all the strips in the given media, then fold each strip using forceps and place them in a sterile Petri plate.

2. Use a hot air oven to dry the strips at 50°C for 40 minutes.

3. After that, place the strips in the laminar airflow cabinet for sterilization for 10 minutes.

4. The strips were then stored in a dry, sterilized plastic bottle.

5. One bottle was filled with tap water and the other with distilled water, and they will be kept for 48 hours. The bottle with tap water showed a black coloration, whereas the distilled water bottle showed no color change, retaining the original media color.

Result :-

Sample	Time	Result
Tap water	48 hours	Positive
Distilled water	48 hours	Negative

13/07/2026
The H2S kit in 400 bottles had expired, so the contents were discarded, and preparation of new bottles has been started.

An order for 800 bottles has been received from Sumit Thakre.

We are planning to prepare 500 bottles by 30 July.

19/06/20226

Preparation of Media for 200 H₂S Kit Strips with DBRT Students

The media required for the preparation of 200 H₂S water testing kit strips was prepared along with DBRT students. The following chemicals were used in the specified quantities:

Chemical	Quantity
Bacteriological Grade Peptone	80 g
Dipotassium Hydrogen Phosphate	6.0 g
Ferric Ammonium Nitrate	3.0 g
Sodium Thiosulphate	4.0 g
L-Cysteine HCl	0.5 g
Liquid Soap	4.0 mL
Distilled Water	200 mL

DBRT students actively participated in the preparation of the H₂S media. They learned how to accurately weigh chemicals, prepare the media in the correct proportions, follow laboratory hygiene and safety practices, and carry out the complete media preparation process. This hands-on practical session enhanced their technical skills and understanding of the preparation of H₂S water testing kits.

Two water samples were taken from kitchen water after treating the water with a UV tube.

• Sample 1: UV treatment for 15 minutes – Positive
• Sample 2: UV treatment for 30 minutes – Negative

Water Testing Conducted This Month

1. Shruti Amol Jadhav

• pH: 6.9
• EC: 88
• TDS: 45
• Bacterial Test: Negative

2. Ambika Milk Collection Centre (Kanersar)

• pH: 6.5
• EC:114
• TDS:60
• Bacterial Test: positve
  
  Water Testing – Rahul Bagate
• Sample 1:
• pH: 6.8
• EC: 88
• TDS: 44
• Bacterial Test: Negative
  
• Sample 2:
• pH:
• EC:
• TDS:
  
  
  
  
  18/08/2026
  
  
  
  Water Bacterial Testing – Campus Samples
• Water samples from three locations on the campus were tested for bacterial contamination:
• Dream House: Positive
• Kitchen: Positive
• DIC Hostel: Negative