Effect of Salinity Intrusion on Food Crops, Livestock, and Fish Species at Kalapara Coastal Belt in Bangladesh

Table 3

Description of quality control (QC) for the determination of salinity indicators in water samples across the Kalapara coastal belt in Bangladesh.

Salinity indicators in water	Container	Volume (ml)	Sampling and transport	Preservation	Maximum holding time	Storage	Remarks
Salinity %	Polyethylene plastic bottle	500 ml	Filled bottle to exclude air	—	Determined on the sampling locations	Analyzed immediately	The meter was calibrated on the day of use
Conductivity (µS/cm)	Polyethylene plastic bottle	500 ml	Filled bottle to exclude air	—	Determined on the sampling locations	Analyzed immediately	The meter was calibrated on the day of use
TDS, mg/l	Polyethylene plastic bottle	500 ml	Transported under ice and filled container to exclude air	—	Held for 7 days before analysis	Stored in refrigerator at 4°C	Total dissolved solids (TDS) also known as “filterable residues”
pH	Polyethylene plastic bottle	100 ml	Filled bottle to exclude air	—	Determined on the sampling locations	There was no storage in refrigerator	The meter was calibrated on the day of use
Fluoride (F^−), mg/l	Polyethylene plastic bottle	500 ml	Not maintained	—	7 days	—	—
Chloride (Cl^−), mg/l	Polyethylene plastic bottle	500 ml	Transported under ice and filled container to exclude air	—	Analyzed on that day	Stored in ice box at 4°C	—
Nitrite (), mg/l	Polyethylene plastic bottle	200 ml	Transported under ice	—	2 days	Stored in refrigerator at 4°C	—
Bromide (Br^−), mg/l	Polyethylene plastic bottle	500 ml	Transported under ice	—	Analyzed within 7 days	Stored in refrigerator at 4°C	—
Nitrate (), mg/l	Polyethylene plastic bottle	500 ml	Transported under ice	Acidified with HCl to pH < 2	7 days with acidification	Stored in refrigerator at 4°C
Phosphate (), mg/l	Polyethylene plastic bottle	300 ml	Filled bottle to exclude air. Filtered on site (0.45 μm cellulose acetate membrane filter). Transported under ice	—	2 days	Freezed (−20°C) after filtration	—
Sulfate (), mg/l	Polyethylene plastic bottle	100 ml	Filled bottle to exclude air. Transported under ice	—	7 days	Stored in refrigerator at 4°C	—
Sodium (Na^+), mg/l	Polyethylene plastic bottle	500 ml	Filled container completely to exclude air. Transported under ice	Acidified with nitric acid to pH < 2	Analyzed within 1 month	Stored in refrigerator at 4°C	Acidified for the determination of other metals in the sample
Potassium (K^+), mg/l	Polyethylene plastic bottle	500 ml	Filled container completely to exclude air. Transported under ice	Acidified with nitric acid to pH < 2	Analyzed within 1 month	Stored in refrigerator at 4°C	Acidified for the determination of other metals in the sample
Calcium (Ca^2+), mg/l	Polyethylene plastic bottle	500 ml	Filled container completely to exclude air. Transported under ice	Acidified with nitric acid to pH < 2	Analyzed within 1 month	Stored in refrigerator at 4°C	Acidified for the determination of other metals in the sample
Magnesium (Mg^2+), mg/l	Polyethylene plastic bottle	500 ml	Filled container completely to exclude air. Transported under ice	Acidified with nitric acid to pH < 2	Analyzed within 1 month	Stored in refrigerator at 4°C	Acidified