CSVHelperExtentions.cs

public static class CSVHelperExtentions
{
    public static string ToCSVString<T>(this IEnumerable<T> objectToConvert) where T : class
    {
        using (var memoryStream = new MemoryStream())
        {
            var config = new Configuration();

            using (var streamWriter = new StreamWriter(memoryStream))
            using (var csvWriter = new CsvWriter(streamWriter))
            {
                var options = new TypeConverterOptions
                {
                    Formats = new List<string>() { "yyyy-MM-dd HH:mm:ss"}.ToArray()
                };

                csvWriter.Configuration.TypeConverterOptionsCache.AddOptions<DateTime>(options);
                csvWriter.Configuration.ShouldQuote = (field, context) => true;
                csvWriter.WriteRecords(objectToConvert);
            }

            return Encoding.ASCII.GetString(memoryStream.ToArray());
        }
    }
}